User blog comment:JaphethMario/Goomba vs Koopa. Super Mario Rap Battles/@comment-6632076-20171219225540/@comment-6632076-20171220010849

Just a few other suggestions

Geno vs Kamek

Rosalina and Luma vs Peach and Starlow

Yoshi vs Birdo

Wart vs Tatanga (forgotten Mario villains)