What would be the worst devil fruit combination for Blackbeard to have?

[Warmmedown]

Say he no fruit powers. And now he's going to eat two fruit. Which would be the worst combination to have together? Ones that cancel out each other would be the worst.

Redundant combo: Fujitora gravity and baroque works weight manipulation

Cancel: ?

 

[SSJ2]

Luffy and Enel's fruit would make a good combo.