Havok or ProfX?

This is a weird question in my opinion. They are such different champions that overall have different applications when tackling content.

Unless you're ranking up someone because you need a Korg counter (the one application they share), you should be analyzing which champion will help you more in completing what you need next.

Djin

Which one to rank up first?

Havok is better if you plan to run him as the only mutant on ur team, Prof x is better if u run other mutants with him, also has huge benefits from boosts

I have Sabretooth, OR, Namor and SPX ranked up.
So ProfX seems obvious choice then.

I like them both. I have a duped R2 Prof. That made the choice easy. I’ll R5 Havok at some point.

Good problem to have.

Lol. I was also going to include Sunspot in this but I don't like to play with him.