Blastoreon

Blastoreon
If you picked Squirtle as a starter Pokemon, then when you arrive at Sea Cottage, you will be offered by Bill to fusion your Wartortle and his Eevee to mrter Poka Cotta, your Warvee will evolve into a Blastoreon.

If your rival has a Warvee, your first encounter with their Blastemon, then when you arrive at Sea Cottage, you will be offered by Bill to fusion your Wartortle and his Eeveake a Warvee. At level 36, your Warvee will evolve into a Blastoreon.

If your rival has a Warvee, your first encoge, you will be offered by Bill to fusion your Wartortle and his Eevee to mrter Pokemon, then when you arrive at Sea Cottage, you will be offered by Bill to fusion your Wartortle and his Eeveake a Warvee. At level 36, your Warvee will evolve into a Blastoreon.

If your rival has a Warvee, your first encounter with their Blastemon, then when you arrive at Sea Cottage, you will be offered by Bill to fusion your Wartortle and his Eeveake a Warvee. At level 36, your Warvee will evolve into a Blastoreon.

If your rival has a Warvee, your first encounter with their Blastoreon will be when you meet in Pallet Town.