I'm quite interested in this set. Do you think RestTalk Gyara pairs well with the Gyaradosite, or is base forme Gyarados better suited for the same slot?
Regular Gyara's got arguably better defensive typing (resistance to Fighting, immunity to Ground), and has the added bonuses of leftovers, permanent Intimidate, and not taking up a mega slot. I imagine as with any Mega Gyara evo you hold on to the base forme for all its advantages until its necessary to Mega Evolve for some specific purpose: the added bulk, dropping the flying-typing, Mold Breaker Waterfall, etc. Can you talk about how you play your RestTalk Mega Gyara, or do you have any good replays?
I'm also wondering if Suicune, with the extra bulk, doesn't do the same thing better or if you think they're different beasts all together. Of course Mega Gyara isn't instantly walled by Gastrodon, Jellicent, Toxicroak and friends and actually turns them into liabilities. Basically I've been wanting to use a RestTalk Gyarados but wasn't convinced about its viability.
A lot of very interesting questions there. For the first part, I would definitely say that Gyaradosite is a good choice for RestTalk. I'm going to just compare them versus 252/252 Attacks Mew, using Base 100 Normal and Special Attacks, assuming it switched in after Intimidate:
Normal Gyarados w/ Leftovers:
252+ Atk Mew (No Move) vs. 252 HP / 152+ Def Gyarados: 93-110 (23.6 - 27.9%) -- 86.5% chance to 4HKO
252+ SpA Mew (No Move) vs. 252 HP / 100 SpD Gyarados: 90-107 (22.8 - 27.1%) -- possible 5HKO after Leftovers recovery
Mega-Gyarados:
252+ Atk Mew (No Move) vs. 252 HP / 152+ Def Mega Gyarados: 73-87 (18.5 - 22%) -- possible 5HKO
252+ SpA Mew (No Move) vs. 252 HP / 100 SpD Mega Gyarados: 73-87 (18.5 - 22%) -- possible 5HKO
The difference between normal Gyarados with Leftovers and Mega-Gyara, defensively, is very small, but Mega-Gyara has a touch more survivability. When it comes to typing, both have merits: Water/Flying is sturdier as typing, but Electric sends fear through any user, and with Rotom-W being almost omnipresent, it's not comfortable. Water/Dark loses Fighting and Bug resist and Ground immunity, but gains Dark and Ghost resists as well as a Psychic immunity. It's an odd trade-off and oftentimes, not worth it. It requires even more careful play.
I don't have any good replays because I generally forget to click save replay as the feature was down for so long (that and my battling is atrocious!). However, when playing with it, I study the physical attackers through some baiting with my defensive core. Generally I use Gyarados mid to late game. If Gyarados gets in, all's well, and you can Dragon Dance for at least one turn. Then, it's a game of avoiding SE damage. In the anecdote of a mixed Aegislash battle, where it has Ghost/Fighting attacks both SE and NVE to Mega-Gyara, it's better to stay in normal Forme as long as you can. RestTalk Gyarados is unlikely to be broken easily by anything other than SE damage, and because Mega-Gyarados has a rather different damage chart, it's interesting to play with.
However... Normal Forme Gyarados has its advantages, in resistances. Mega-Gyarados has an astronomical Attack stat, even univnvested, and is not stopped cold by Water Absorbers and does huge damage to those not named Jellicent. Offensively, Mega-Gyarados performs better. Defensively, Normal Forme Gyarados does better. This is where one has a problem...
Why I like using Gyaradosite, though, is the choice. You lose passive recovery on Normal Forme but you have the option to change up your resistances when the situation calls for it. You can play mind-games with your opponent also: if you evidently have no other Megas, chances are they won't switch Rotom-W in on you, fearing Mold Breaker Earthquake.
By all means, do try RestTalk Gyarados, normal and Mega options are both viable. Suicune is interesting also, but in all honesty, I would prefer to use Gyarados: Suicune has become a one-trick pony (who hasn't heard of CroCune?), and generally people can suss it out by seeing it alone and counter it, and is hard walled by the very same things that wall normal RestTalk Gyarados. The difference is that Gyarados has a vast array of movesets that are viable, which makes this particular set a bit more surprising. Suicune's predictability hurts it for sure.
TL;DR try bulky mono-attacking mega-gyarados because idk it's good and stuff