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I wouldn't say its unviable but it's also not amazing either. Kinda mid-ish? Your miles may vary on how you do, newbies and scrubs will get caught off guard by it but top players will have answers for it.
So, am I wrong in assuming that the new mirror herb is meant to expedite egg moves now? IE: Getting Azumarill belly drum through a picnic with a Hariyama that has the move instead of breeding it with a mon from the poliwag line?
Nobody seems to have bothered with making one. Right now is also an odd time to go making it as the whole meta is about to shift with home's imminent release.
Well 1. Rather hard to offer a way to improve a team when you didn't even offer up what you were looking to improve on in your initial post. What are you struggling against? What have you found to be not pulling its weight? 2. Just because you don't like the answer you're given, doesn't mean...
Pick one. Trick room is already gimmicky enough as it is, wonder room is even gimmickier. The teams that are considered top tier, aren't because they have a strong gimmick. It's because they have strong win conditions no matter the situation.
The win condition of a theoretical double room...
LF 4IV+ spitbacks; G-Ponyta, Larvitar, other Shield exclusives, Stonjourner, HA mons
FT; 4IV+ spitbacks of my own; Isecue(with belly drum and icicle crash), HA Scraggy, HA Eevee (with yawn). Also have a 31/0/31/31/31/0 Quiet Honedge available