Mega Steelix new ability ????

hi guys. I really love using Steelix ( please, dont ask me why). however, i feel like mega steelix's ability 'sand force' is too useless. this is what pokedex said about steelix: Tempered underground under high pressure and heat, its body is harder than any metal (pokemon X).

i feel like mega steelix could have a new ability called 'forged steel'. this ability gives mega steelix immunity to fire moves; and if mega steelix is hit with a fire move, its Def and SpD will increase one stage.

another pokemon i think should have this new ability is mega excadrill. yes, excadrill deserves a mega and this 'forged steel' ability will suits excadrill

tell me what you guys think. thanks

On a role-playing standpoint, solid idea, but moreso defensive side, rather than both D. and Sp.D....I think it makes more sense from both a role-playing aspect and keeps it from being maybe a bit much from a competitive standpoint...

I like the idea!...