Zamazenta - Hero of Many Battles

With Zamazenta holding Rusted Shield, its second form (Crowned Shield) is activated and then becomes Fighting/Steel type. While in its Crowned Shield form, the move Iron Head becomes Behemoth Bash for the whole duration of the battle.

POKEFELLA BUILD

Zamazenta @ Rusted Shield
Ability: Dauntless Shield
EVs: 252 Atk / 4 Def / 252 Spe
Jolly Nature
- Psychic Fangs
- Iron Head
- Crunch
- Close Combat

If you want a build other than what is shown here, you can choose the listing Any Custom Pokemon.