you probably anticipated me to say this, but Heatran doesn't have reliable recovery so it's not as consistent of a wall as it'd like to be that's not to say it's not good though, that 4x resistance to Fairy really helps considering that Altarianite is one of the best Mega Stones in the meta (other than Extreme Speed, it's also used by the likes of Noivern) and Heatran hits harder than Skarmory