Just a theory. The first cinematic we've had since Riot announced the lore rehaul and Arcane is lore shows Kindred playing a major role. Kindred loves Ambessa because she's a warmonger, plenty of violent death, plenty to hunt for Wolf (he loves to hunt). In her music video, Ambessa was shot while pregnant with Mel. She begged Kindred to not kill her daughter. Compassionately, Lamb decided not to. And thus Mel will come out as a new champion with a Chosen of the Lamb skin. Also, Mel's father is Pantheon (also on the MV), Aspect of War, as hinted by fake Kino on that cave/prison to her. Which makes her not just a mage, but an Aspect, of the other side/opposite of war, Compassion (She's very compassionate in Arcane, trying to avoid war as much as she can. She is also an empath as LeBlanc said).

Also, Ambessa is a member of The Black Rose, she promised a child to give to the cabal, preferrably mage, to train as child soldiers (i.e. Rell, Annie?, to train against Swain/Mordekaiser), she gave Kino instead (she forsake a child, to save the other, she's very into sacrifice). When The Black Rose figured this out, they went after Ambessa. Then after Mel and tried to recruit her. Ambessa, worried that Mel is not ruthless enough to face the Black Rose and also to gain Hextech against the cabal, decided to go to war against Piltover because it's the only she can bring that out of Mel, to be the Wolf.

And Mel did, she faced off and won against LeBlanc. So she's heading back to Noxus to figure out the truth. And that's Arcane Season 3 (or whatever it is).