Hidden Power doesn't exist in Gen 9. Although you can use Tera Blast with the appropriate Tera type to replicate that. Note that using your Tera on Heatran will also change your defensive typing for the 3 turns (?) it lasts.

[–] LordAmplifier@pawb.social 1 points 11 months ago

It's good to know that Hidden Power doesn't exist in Gen 9, thank you :3

Heatran would probably stand a slightly better chance against some of them with Tera types, I reckon. Tera Grass would give it a Ground resistance (Flying would make it immune, but then it'd be vulnerable to Rock-type moves and have no way to deal significant damage), and Grass-type Tera Blast would safely 2HKO Hippowdon, for example. Even a mono-Fire typing would allow it to survive Hippowdon's Earthquake and, with some luck, 2HKO with Fire Blast.