Xeno 2 changes half the voice cast (includioNG SHION AND KOSMOS YOU STUPID IDIOTS WHY). Shion mostly suffers as a "sister hating her brother" complex and little else interesting. The game was about Jr. And Albedo...so bleh.
Ep. 3 bring the good actress back, and she nails the mood, but let's just say they course corrected WAY too fucking much to give her every piece of major screen time and plot relevance, but turn her into a tragic heroine who bitches, moans, gets lost in crazy plot twists so dumb, it makes SO3 look good...and...yeah.
Ep. 2 and 3 do NOT do Shion the character any favors, even if the actress in 1 and 3 (Lia Sargent) plays her about as well as one could.
I still like Shion, but I have to admit (episode 3 spoilers) that when she is reduced to whining Kevin!!!111 before actually turning on the party, it's pretty darn bad. I like the subversion of typical genre clichs with Allen being a love interest without being a combat-focused character or party member. I suppose it's more of an inversion of gender than subversion though.