Alomomola @Damp Rock
Any Nature
Hydration Ablity
EVs 252HP 252Sp.A 4Spd
Rain Dance
Rest
Waterfall
Toxic
My personal Tank. As soon as battle starts, use Rain dance, Damp rock makes it work for 8 turns, counter with Waterfall for water weakness. Toxic for bulky enemys or foes with water absorb and stuff. Use Rest when HP is low to heal, Hydration ablity wakes it up if it's rainy, if rain goes out, use rain dance again.
Alomomola has, MASSIVE HP, can max out at 534!!! yes, 534!!!!! it has the 5th highest HP of all Pokemon! Just beaten by Wailord. Most foes need around 5-6 hits to kill it, but I have Rest!
Once I had a friend battle, his Zekrom's Fusion Bolt did 496 damage. and it was a critical hit.