Hardest Relative NPC

Whoops :P

Even then, only two have mentioned her

That's because she wasn't a problem as far as I remember .-.

I would say BW1 Ghetsis and BWB2W2 Cynthia. Ghetsis's Hydreigon is just powerful. I lacked an OHKO while it OHKO'ed all of my mons (except Musharna, and it didn't do much).
I would also rate Cynthia as being hard because I almost lost, even with a level 100 Genesect and level 75-85 Tyranitar/Excadril/Lucario/Terrakion and a level 87 Reuniclus.

Ghetsis is a pathetic pushover in all the games with a Throh with Revenge. I took a Dragon Pulse that did like, what, 45%, and I easily KO'ed with Revenge. Talk about dissapointment.

Yeah the Hydreigon sucks frankly.

I also found Cynthia rather easy with one thing...
WHY THE HELL ARE YOU SPAMMING REST ON YOUR MILOTIC CAN YOU NOT SEE IT IS DOING NOTHING GHSESDGHAPSD!!!!!

Is Step 1 modifiable for Nuzlockes in which you don't have Sandshrew or Pidgey?

I truthfully had trouble with Cynthia when I first fought her in Diamond and Pearl. Her Garchomp is a vicious beast O.o

On a scale from 1 to 10 (of the games I've played through):

DP:
Roark: 2 (four words: Turtwig, Piplup, Monferno, Machop)
Gardenia: 3 (Staravia is awesome.)
Maylene: 3 (Yeah in DP you should just get a Starly and kill the game with it.)
Wake: 5 (If you got a Shinx you're only worried about Quagsire. If you didn't...well...you got the TM for Shock Wave I guess?)
Fantina: 4 (A lot of stuff beats those ghosts, they're not the most bulky things out there.)
Byron: 2 (All the starter's final evolutions own the shit out of him, and then if you picked up any Fighting-type earlier, or any Ground-type, or...yeah you get the point.)
Candice: 4 (Good luck beating her with Torterra lol. But Staraptor beats her, haha.)
Volkner: 1 (If you haven't already, go get a Gible. Also, if you play Diamond you have access to Dialga at this point, who simply laughs at Volkner.)
Rival: 4 (He knows how to use FWG! But Staraptor is still good for facing him. Just get a Starly and it'll do work for you.)

Aaron: 3 (If you don't have a Staraptor you are an idiot.)
Bertha: 7 (Torterra laughs at this very hard. But everything other starter just gets killed. Even Staraptor doesn't make much headway. Your best bet is any Grass-type, and Roselia is pretty much the best you get.)
Flint: 6 (Um...use Palkia? lol. 3/5 of his team is not Fire-type. All your starters will die here. Staraptor is decent but not foolproof. Also, Double Team+Baton Pass Drifblim...UGH.)
Lucian: 8 (This one's actually hard. Staraptor is again good because of its high speed and attack, but falls a little short here. Alakazam packs quite a punch. If you got a Spiritomb, use it. Weavile+Staraptor+Infernape deals with this pretty well, but a lot of players wouldn't be using that.)
Cynthia: 9.5 (Dat Garchomp. Spiritomb can PP stall you a bit, so watch out. Milotic has Mirror Coat, so don't try Leaf Storming it. All in all, tough, but not impossible by any means.)

Pt:
Rival: 7 (First battle...UGH. He does get a lot better than the last games, making this one a bit harder.)
Roark: 2 (see DP)
Gardenia: 3 (see DP)
Fantina: 8 (Haunter is just so annoying, Duskull burns your physical attacker, and finally Mismagius just slaughters you. Have fun beating her without quite a bit of grinding or luck.)
Maylene: 3 (see DP)
Wake: 4 (If you have troubles with him go into the Safari Zone and get a Tangela.)
Byron: 3 (Bit harder thanks to Magneton, but a well-leveled Empoleon still solves the problem, and the other starters still kill him. Also at this point you already have access to Gible, and Gabite eats this gym alive.)
Candice: 6 (Froslass is a BITCH. Also the gym is just so time-consuming, especially after you lose to that fucking Froslass.)
Volkner: 1 (Garchomp! Giratina works too I suppose. Or Golem. Or Steelix. Or...)

Aaron: 4 (Give your Staraptor Aerial Ace to deal with Yanmega's Double Team. Otherwise, you need quite a bit of luck.)
Bertha: 6 (Got easier for Empoleon, a bit harder for Torterra. If you have Infernape, try using Tangrowth (which you should have gotten to deal with Wake earlier).)
Flint: 5 (His mons are actually Fire this time! Which makes life a lot easier...unless you're using Torterra. If you are, any Water-type works well, just watch out for coverage moves like Thunderbolt and Solarbeam.)
Lucian: 6 (A LOT easier. A well-leveled Staraptor beats him. If you don't have that, then try using any Dark-types you have, or just hit them with your hardest attacks. They're not as high-leveled anymore.)
Cynthia: 8 (If you have a Garchomp higher-leveled than Cynthia's, use it. It will crush her. If not, a well-leveled Staraptor is good. Certainly nowhere as hard as DP.)

HGSS:
Rival: 3 (He's supposed to be a challenge? lol)
Falkner: 5 (You'd better grind, because otherwise you pretty much lose. Also if you picked Chikorita you are mentally retarded.)
Bugsy: 4 (Get a Geodude, otherwise have fun trying to beat Scyther. There's a reason that thing got banned from LC.)
Whitney: 11 (GLHF)
Morty: 7 (Gengar is fucking strong, and you will die to that Shadow Ball...if you have Scyther Agility+Swords Dance+Pursuit (Game Corner FTW!) is a very easy way, but you have to be at +6 at lv. 23 or 24 to OHKO Gengar...so...just use normal-types and pray things go your way I guess?)
Chuck: 3 (You can get Spearow very easily, and there's even a guy that gives you a lv. 20 Spearow. Fearow kills Chuck so badly...)
Jasmine: 3 (Use a ground-type.)
Pryce: 3 (Jasmine has stronger mons lol. Just use a Fighting or Fire type, or whatever you have really.)
Clair: 9 (Gyarados's Dragon Rage is usually a 3HKO on you at this point. Kingdra will 2HKO everything in your team. You can't even use Ice-type moves that effectively here.)

Will: 4 (Ghosts and Darks work like magic here. Also, a lot of things get Crunch.)
Koga: 5 (A high-leveled Kadabra or an Alakazam beats everything but Forry. Otherwise, he's more annoying than actually dangerous.)
Bruno: 4 (Invest in an Alakazam for the E4, it really helps. If you don't have that, then use Flying-types. If you don't have those, use Gengar or Misdreavus.)
Karen: 8 (Wait she's Dark-type? Anyways, she has lots of ways to fuck with you, like Destiny Bond, Double Team Umbreon, and Houndoom. Just tough it out.)
Lance: 7 (Fast attackers with Rock and Ice-type moves kill Lance before you can say "knife". If you don't have those, tough luck.)

Post-game: 3 (You are way to overlevelled for the last couple leaders, and then Blue's not too bad either.)
Red: 10 (GRIND LIKE FUCK)

BW:
Cheren: 4
Bianca: 2
Striaton trio: 14 (seriously, unless you overlevel them by like 5 levels they kill you)
Lenora: 8 (Watchog is actually dangerous for once. Also Herdier by itself is deadly.)
Burgh: 2 (Go get a Darumaka.)
Elesa: 6 (Stealth Rock Dwebble is a good thing to use, Krokorok is too, if you don't have either you are dead.)
Clay: 3 (Deerling/Ducklett, Scraggy)
Skyla: 2 (Chargestone Cave is anti-Skyla)
Brycen: 1 (You have access to Gurdurr/Conkeldurr, Scrafty, Klang, Mienfoo, Ferrothorn, and a crapton of Fighting-type coverage. There really is no excuse for losing to this guy.)
Drayden: 4 (You just got through Iccirus City. If you forgot to pick up a Vanillish or any Steel-type than you are an idiot. lv. 45 Fraxure also destroys him.)

Shauntal: 4 (If you have Scrafty, use him. If not, just hit her Pokemon. Only Cofagrigus is really that annoying.)
Caitlin: 3 (Scrafty. I suppose you could also use any powerful attacker really.)
Grimsley: 3 (Scrafty. Or any Fighting-type moves.)
Marshal: 6 (Scra---no wait. This is actually quite hard. Packing a Psychic-type isn't enough, you'll also need stuff that can take Stone Edges. This is not a job for Beheeyem alone.)

N: 3 (Click Dragonbreath and your legendary Dragon will eventually beat his. And then you sweep the rest of his team. Also, you can set up one Dragon Dance with Haxorus and watch stuff die.)
Ghestis: 8 (Hydreigon stops your sweep. And starts its own. Unless you set up DDs with your Haxorus. His other mons are also decent.)

BW2:
Hugh: 2 (You don't fight him that much, just join him in battle.)
Cheren: 7 (Lillipup WILL sweep your team. This is one of the best reasons to get Riolu.)
Roxie: 1 (Use Magnemite.)
Burgh: 1 (Magnemite/Lucario/Darumaka/...well you get the point)
Elesa: 4 (Quite easier, especially thanks to new tools that can be used now.)
Clay: 2 (Easy as ever.)
Skyla: 1 (Magnezone makes her even more of a joke.)
Drayden: 3 (You've got Steel-types by the bundleful. Use them.)
Marlon: 5 (Really, he's not THAT hard...)

Shauntal: 4 (see BW1)
Caitlin: 3 (see BW1)
Grimsley: 3 (see BW1)
Marshal: 6 (see BW1)

Iris: 8 (I have learned to fear Archeops. It's worth it to bring Metagross here just for Bullet Punch. Magnezone is also nice, since it lacks Earthquake (lol).)

I think that you're talking about Chansey, it's imposible to see a Bliss on Leaf Green until you get the National Dex.

I have to say norman in R/S was one of the worst to face. What idiot decided to give you terrible grinding options before such powerful pokemon needs to be shot. I always skipped well ahead of winona to get either spheal or snorunt to deal with that nasty altaria, or I had enough coins to purchase ice beam for my water type.

Agreed about misty in R/B.

Whitney...oh god no. Even worse in HGSS thanks to the scumbag who decided her miltank got to hold a lum berry, making status even worse to use. Didn't have a huge problem with morty since I had crobat at that stage of the game, which did the job due to bite.

Clair was insane, bad enough in G/S but at least kingdra had hyper beam at worst as a nuke weapon, but HGSS actually give good weapons to kingdra in dragon pulse, and it getting perfect neutral coverage at that point since there wasn't any way not involving trading to get empoleon in that game.

Karen in the original G/S was pretty hard from memory. Her houndoom always seemed to do huge damage with its dark/fire combo's, and I always seemed to fall short with surf from my water types.

Yeah Justy it's so annoying with his Sandstorm and Double Team strategy...I hate that and also his pokemon levels are on early 40 so hard if you try it on early game when you are between 29-31, but yeah when you catch Quagsire and purify some pokemon it's pretty easy to beat. For Suicune, it is I don't know why, but it's more easy for me to catch Raikou and even Entei, but Suicune it's hard to snag for some reason.

I actually never had a problem with Whitney in HGSS since I discovered Dratini (Dragon Rage cleanly 2HKOes). But before that...ugh...

Early in my Y run-through, I fought a trainer with a Volbeat. It had Prankster and used moves like Double Team, Confuse Ray, and Moonlight.

Fuck Red.
Fuck Cynthia.
Fuck everyone else.
That Volbeat was the hardest friggin' thing I've ever fought. Period.

Ahh memories. I never had an issue with any of the trainers in any gam, except for Claire. I only had a Typhlosion and an Ampharos then, and neither were over leveled enough to plow through her resistances

My one big problem was from the first time I ever ran the elite four in Blue version. I had the three legendary birds, a Lapras HM slave, a Pidgeot, and level 83 Charizard... Lmao

All my other pokes were generally to weak or didn't have decent attacks except for my starter. By the time I got to lance and Gary I didn't have any PP left to do anything.

For me, it would have to be Korrina in X. Her Pokémon were all easy EXCEPT for Hawlucha. OH MAN FLYING PRESS PISSED ME OFF! I don't even know what would possess Game Freak to make a move that's Fighting type AND Flying type at the same time. Korrina's Hawlucha is like the new Whitney's Miltank. My Combusken was my strongest Pokémon, and it took supereffective damage from a move that wasn't even primarily Flying!!!! >:(

I beat the game now, so it doesn't matter.

I used Delphox. It took 10 damage the entire battle. From Mienfoo's Fake Out.

Talonflame works even better.

This guy...lol...this was the second time I had my starter faint. The first time is when Fennekin failed to kill Viola's Surskit.

Oh that guy...I remember that I was training my Bagon and then found this guy...I change Bagon for my Honedge, and it was murdered by Bulldoze, then I sent Braixen, and was murdered too, thanks to the Sturdy of Sawk, after lost 3 members of my team, and defeat it, for being just a random trainer it was a hard battle.

I wish that were the case. I'm up to the 7th gym (leveling up a few mons before taking it on) and the only gym that has seriously challenged me so far is...Viola's. To be fair, I could've been in strife against grant but luckily take down from amaura missed my skiddo, which allowed me to leech seed/synthesis stall his tyrunt once amaura went down.

Honedge + charmander has made the game WAY too easy for me. Megaevos early game...what a poor idea. Megazard X one shotted all of Ramos' pokemon. Then again, my opinion of the gyms are that they are a total joke ever since they got restricted to 3 pokemon only...

Oh and bulldoze spammage from throh and sawk...damn them both and all trainers who used them. Really wish I thought to have a flying pokemon at that point in the game. Honedge was just bulky enough to deal with that crap.

I skipped that guy on my first play through.. and had the wonderful experience of losing half my nuzlocke team to him yesterday :(

It has to be youngster Joey. His top percentage ratata was just too much to handle.

+1 for that goddamn milotic in RS. What in the actual fuck.