This coalossal already is planned to have endure and weakness policy with steam engine as it's ability I need to decide what the other 3 moves should be but I can't coalossal has two 4× weaknesses and two weaknesses so this set needs to have some sort of coverage :D
Coalossal has a way better Physical movepool, but Scald covers more weaknesses.
Coalossal @ Weakness Policy
Nature and EVs are whatever you want, but I recommend Modest nature and 252 SpA / 252 Spe / 4 Def
Ability: Steam Engine
-Ancient Power/Earth Power
Scald covers Rock and Ground types.