User blog comment:Weew1213/Dementor vs Ringwraith "Soul Sucking Demons" (Season 1 Finale and Halloween Special)/@comment-4454770-20151016151251

Ringwraith easy. They can use magic, they were former warriors who had previous experience, and can think and strategize. The dementors are just soul sucking beasts who functions by instinct. They can fly, but the Ringwraiths can teleport short distances. And the Ringwraiths are already dead so the kiss won't affect them.