Listen up people. There is alot of lies and misconceptions running around here and I will do my best to correct them.
1. Blackbeard IS IN FACT A LOGIA.
-A- He can create and control shadow as well A BECOME IT. however
-B- The nature of darkness is the devouring gravity. It unlike other logias by its nature CANNOT let attacks pass through without harm. It nature is to capture and consume thus the attacks can be absorbed but by absorbing the attacks the user suffers them. THUS
-C- Blackbeard can stop himself from burning by absorbing the fires on him, or perhaps absorb an attack as it comes in LIMITING its damage but he cannot let it pass harmlessly through.
2. Blackbeards relatively undamaged state comes from his DURABILTY. He is a tough mofo without any of the powers he has. "I can take more pain than a normal person" he says.
3. THERE IS NO RETURNING ATTACK 2X, THAT IS A FAKED SCRIPT LIE!!!
4. Blackbeards power is not Light phobic. If it where his arm couldn't become shadow like it does. Crocodile couldn't transform while wet. Blackbear can transform when in the presence of a gigantic mini sun. Look at his hand. Whatever its weakness its NOT LIGHT PERIOD! NO white holes, no particle fountains no light light fruits. Gomu gomu no DAME!
5. Blackbeards powers means that he can always suck in the real person and then once he holds them he supresses their devils fruit powers, perhaps other powers, but not their strength. So he is only half of sea stone, and probably has other benefits against non-users.