Unless, the tentacles can heal him, I don't see what is the point of giving him the tentacles or furthermore bringing him back. Yes, he has Ock-features and a European accent, but besides that, according to myself and other posters on here, Kafka was one of the worse additions to this sequel and was a giant, walking, talking cartoon character. He was borderline Schumacher's Batman films. He just felt out of place completely.
Besides, the dude wore lipstick. I would not want to see Dr. Octopus, a man who is incredibly smart and tough, be reduced to a gender-confused parody of Dr. Frankenstein. And I'm not saying this to be mean or insensitive or anything, it's just Kafka was just that an odd parody of black-and-white horror films and reminded me of Mike Myers' Dieter from Sprockets ("SNL") than a character to be taken seriously:
I would rather see Carolyn Trainer become Lady Octopus over Dr. Kafka becoming Dr. Octopus over Dr. Otto Octavius.