The numbers are correct, but your conclusion is not. 50% is the multiplicative inverse of 200%, so your attacks will in fact do twice as much damage against a target at -2. Any negative defense modifier will have the same effect as the equivalent positive attack modifier.
The actual damage equation doesn't use HP at all, but since in virtually all cases your main concern is the percent of total HP (where the HP IV obviously matters) they're both important. Which one is more important is more complicated, and depends on the Pokémon's base stats and what spread you plan to use.
The game can use the DSi's ability to detect internet connections. It's the first game that made use of that feature, apparently. It will region lock you if you try to play a Japanese version of B/W on it.
First off, Thundurus is in the Uber tier, which includes all the overpowered legendaries and such. The tier of your team is determined by which individual Pokémon is in the highest tier, so using Thundurus forces you into Ubers, while the rest of your team isn't really powerful enough to work there.
I believe that is a mistake. Report it in this thread if I'm understanding it correctly.
So Keeping Gengar, who are solid replacements for the rest of the team? in your opinion.
taken from the onsite page,
Like the page said, with Chlorophyll Jumpluff has insane speed under the sun and is able to greatly support its team. With moves like Sleep Powder/Stun Spore/Leech Seed/Substitute/Encore it can greatly cripple opposing teams. Just because a pokemon may seem "weak" doesn't mean it always is, every pokemon has its unique niche that your team may need.
If you allow weather, I believe that honor goes to Darmanitan's Flare Blitz in the sun. Edit: never mind, Kyogre's Water Spout just barely beats it. Without weather, probably Deoxys-A's Psycho Boost. Note that I did not do an exhaustive search of every possibility, so I may have missed something, but I think that's it.
In the sun Charizard's Solar Power-boosted Blast Burn is stronger than Darmanitan's Sheer Force-boosted Flare Blitz (not that using Blast Burn is a good idea) and Kyogre's Water Spout (in the rain, obviously).
a woman out side of nacrene city gives it to you, i think this would be better of in the orange islands in future.
there's a girl at the entrance to Pinwheel forest
Much obliged. This is going to help heaps against Lenora and her hell-spawn during my Nuzlocke, as long as I have SOMETHING that can actually use it.
I'd reccomend catching a Timburr in the grass below, help's with Lenora, Burgh, and most other gym leaders.
I was doing a Nuzloke and LEGIT got a Throh as the first poke on that route. It stayed alive until the end, where Ghetsis' Hydreigon OHKO'd every poke on my team EXCEPT that Throh, who OHKO'd back with Superpower and let me beat the Nuzloke 1-0. One of the best feelings I've ever had in Pokemon.
I'd actually like to see someone calc this, and then see if there was anything stronger (in Gen IV).
