Should I roll for Jalter or wait for Merlin?

Jalter is OP; Merlin makes everyone OP

120 SQ is still too few. It is likely you spend them all and get nothing. Better to save up for Merlin. If you really want to try, I would throw in a few tickets just to yolo.

Let's see, double Merlin allows me to do op stuff. Double jalter is basically as good as having 1 jalter.

Speaking as someone who has yet to roll a Waver, I say there's nothing like having a very strong support servant available at will. Merlin is one of the best of those if not the best, and he'll be good to you no matter who else you have in your lineup.

Ultimately you roll for what's in your heart, though, so while Merlin might be more "valuable", if you love Jalter more, I say roll for her.