Michael would be the best choice in general. Only card to out do him would be Cr Caelus and getting him is out of the question
Jay has nice damage but you can supplement him with Greem or go for a Falk who brings pretty nice attack manipulation especially in a mono deck.
Praxie is a bit overpriced in my opinion. I would suggest switching him with the many other useful 3 stars instead.
Michael - best ELO/DT useable Skeelz 5*. Best choice in my opinion
Jay - Good 4* but I personally the 7 power w/o any help is pretty weak especially with revenge needed. Probably take Dr Falkenstien (in mono) & Greem (if u know how to play w/ her) and possibly even Belgosi, Corvus, & Manfred depending on the deck.
Praxie - Overpriced and not worth it. Choose Chiara, Sandro (in mono), Lorna, Snowflake, & Andy Ld