Another similarity between Doflamingo and kaido is that both are able to travel on clouds. It being an alliance arc luffy also had to share credit. Shared credit with law for Doflamingo and shared credit with kid/law for kaido/Linlin
Blackbeard might have a special logia similar to katakuri having a special logia
Blackbeard is an all around fighter. Obviously can brawl but also has guns for marksmanship and a hidden bladed weapon
I still think same way Katakuri against Luffy in wci and potentially Shiryu and laffitte against zoro and sanji that Blackbeard will likely push luffy’s observation haki as well