If Lena has one flaw I don't like it's that she seems like a hopeless battle junkie, for a retired former S-rank adventurer. She could have just told Yuki instead of pushing her buttons so she can have another fun sparring session (or so it seems to me). I thought it was in her best interest to have Yuki in a happy and sound state of mind so she can do her quests well? It's baffling, but best case, maybe Lena is cooking something in the way of an investigation.
Anyway, I'm sad that nobody ever tells things straight to Yuki. Not her beloved but cowardly childhood friend, not her scummy party members, not the guild master she works for. Poor girl is going crazy. Dion, you insensitive bastard.
Proper communication is so hard to find in this story, the only two instances I can remember were when Dion came clean to Eldora about the beginning and to Lena about the betrayal.
Enter this stinky hot and barely covered new alchemist/witch. Probably the new source of fanservice now that Eldora has clothes.