I think these are really really cool! I like the new skills you've added a lot, and I think that staff users desperately need a buff. I'm always a bit hesitant to think about legendary staff weapons because it throws the rest under the bus, but honestly I'll take anything if it makes more than just Elise (and arguably Clarine) viable in more short-term battle modes.
Looking at those stats, it seems like Phelan will be able to put a lot of use to Arcane Duel, though I wouldn't be surprised if something like Desperation would still be better in the long run- mainly because he would still be prone to losing with only 26 Res to make use of it defensively. I can see him being an excellent mage baiter with something like Distant Defence, though, since he'll likely be able to tank a lot more if he can ignore things like cavalry buffs completely, plus he won't have WTD against Cecilia. I do find having the second highest attack of all mages to be scary though, but since it's infantry I think it would still work well. Plus 16 defence is very exploitable.
It's hard to tell whether Liam would be balanced or not in practice, but we could certainly use a Horse Emblem nerf (? kinda works both ways, since he IS on a horse...). Why does the Speed go from 37 to 41 on a boon, though?