I haven't posted on Serebii forums in years... Well, might as well try to help out the community a bit.
Anyways, Cinderace has pretty good physical offensive stats with 116 Atk and 119 Spd. Movepool's a bit weak, though. I'm going to take a wild guess and say it'll end up in UU - I notice on Smogon that there seem to be a lot of powerful Water-types getting OU and Uber movesets fast (Gyarados, Quagsire, Toxapex).
Offensive Cinderace
Ability: Libero (preferred)
Item: Life Orb / Choice Band
Nature: Adamant (+Atk, -Sp Atk) / Jolly (+Spd, -Sp Atk)
EVs: 252 Atk, 252 Spd, 4 HP (or other defensive stat of your choice)
Pyro Ball
Zen Headbutt
U-Turn
Bulk Up / Agility / High Jump Kick
A basic lategame sweeper setup. Bulk Up and Agility buff your stats - Bulk Up for Jolly and Agility for Adamant. If you're running a Choice Band, however, you obviously want an extra offensive move. High Jump Kick is alright. Pyro Ball is your STAB Fire move. Zen Headbutt gives Toxapex pause. U-Turn is there to make a hasty exit if something nasty shows up (*cough* Hydregion *cough*).