User blog comment:B214/Question and Answers 6/@comment-9307023-20200130031045/@comment-10330822-20200131044743

If they didn't bother to make Le Fey the Contracted Magician I would feel more comfortable proposing her, but I think her contracted magician position is meant to be her position.

And while its true that Le Fey won't live as long as the other girls, Issei presumably is immortal, so he'll outlive all of them regardless. Also, with things like what happened to Vasco Strada, I question whether they don't already have a means to allow Le Fey to stay young like the rest.

Roygun, to me at least, makes sense and as a Rook too. She's already been barred from participating as a King, so he acting as a Rook under Issei may be her way back in. Also, it'd be pretty boss for him to have one of the previous Top 3, plus she has so much experience.

Verrine might be a good idea, but I still question if wasting 8 pawn pieces are her is smart. If Elmenhilde is getting added, they'll need those pawn pieces.

Tiamat I feel is more suited as a familiar, since they already Chekhov's Gunned that she is a familiar candidate. My guess is that he wins the tournament, gets her treasure, gives it back, and Tiamat rewards him with a familiar contract for seeing to Ddraig's debt.