Licht's relationship with:
Aria: She highly values him due to his ability. What she did was more of familial thing, as in she considers everyone in her group a family or friends. I don't think there's any love interest whatsoever, unless something happens down the road, but not now.
Rose: Bit of wild card in the term of romance relationship probably due to her parents thing a dozen chapters ago. She highly thinks of him as her friend on the same level as Aria.
Iris/Tisse: They absolutely have no interest in romantic relationship with him. They do think of him as a friend, probably on the bottom of the totem pole.
Dorothy: Probably same level as Rose in the term of relationship with him, whilst at the same time, probably as teacher/student (didn't seem more of it, it seems). She's grateful to him for what he did for her.
Faris: So far, it's confirmed that she's greatly interested in him as her life-long partner. She's very happy that her ability can be used over and over as long as he's in the same clan/group. She claimed that Rose is her rival in the term of romantic relationship. Was Dorothy not in the play as well?
My take:
-Aria: Values Licht for his ability and make damn sure he stays loyal to her so she con continue ruling the underworld (Because who wouldn't treasure an infinite spawn point lol). Will not hesitate to kill him to prove a point however (But only because she knows he'll respawn).
-Rosé: Values Licht as a coworker, but unconsciously feels indebted to him as some sort of a savior. The trip back home made her realized that while she owed Aria for saving her family, she pretty much owed Licht the same for resurrect her (initially, and many times thereafter).
-Iris & Tissé: Made for each other and therefore never wanted a guy in their space. Grateful to Licht for resurrecting them and will return the favor, yes, but nothing more.
-Dorothy: Fellow human, betrayed by her co and therefore easily sympathetic to Licht. May or may not envy his skill and want to try producing an offspring with said ability, but will stick to Necromancy and happily passing on the knowledge to Licht.
-Faris: The only girl to show actual interest in Licht, and for a good reason (They pretty much made an unstoppable combo). Loneliest member of Aria's team and likely longed for a partner (Which Licht is a perfect candidate). Already conscious that other girls may try to one-up her and committed to win Licht over (Hence she took Aria's decree to command Licht for one day as a condition to stay behind).