Rank 5 if you want, and if he's duped. I use mine mostly in AQ, sometimes in war. Great champ, double immune, DoT, ice armor can take sp3s.
Rank him up to rank 4 but no more. For the uses and the matches you will need him he doesn’t need to waste items for a rank 5. He has good utility but he lacks a lot of damage output. If u u do the mistake and bring him against any coldsnap/frostbite immune champ, better quit the fight and replace him with Karnak or any other meme tier, you will finish the fight faster. lol