Since Lohen has a Cryo Vision, I hope he'll be some kind of Superconduct specialist.

Superconduct has never done that well, and I think Lohen presents an opportunity to give us a Chevreuse-like SC specialist. This would finally let my Eula do some real damage.

The question is how he'd end up doing so. I'd do a few things:

1. Make him some kind of off-field Physical DPS, as we have no one who can do that at present.
2. Have him provide a buff that drastically enhances Physical damage (without being another RES shred), but only if your team consists of only Electro and only Cryo (so no Zhongli, Furina, etc).
3. Have him enable Superconduct to lower Electro and Cryo RES, but not by as much as Physical RES. This would uniquely let him pair with characters like Ayaka, Raiden, etc., to let them do more damage and enable certain combinations.

That's just my hope, though. I just don't want Hoyo to kill off Superconduct and leave Eula as permanently unviable.