Thalion

I was really counting on the morsarr and AotS drops T.T

This was my favourite unit on old warhammer fantasy, and still have enough models to make an army of them on AoS 2. Sadly, even if you theme everything arround them instead of just taking the frostheart, i dont think there is a way to make it competitive by its own, you need to add some stuff to it. Im thinking on a Phoenicium City theme, as in AoS lore the godbeasts exists, there might as well be a gigant godly one that aelves of old might take as their god, since the other incarnates are trapped on the past, more interested on extrating corrupted souls from slaneesh than looking over the rebirth of a new civilization, they turned to a greater patron and seek to stablish the realm of rebirth. This way, adding with wanderers for battleline and wizards, the lifesswamp thingy that allows you to bring back models on a big blob of phoenix guard plus a collegiate arcane giving back wounds to the phoenix, can make de ultimate anvil. Maybe some eldrich council help to add monsters and rerrolls and you have something defendable. I wish things were different, but for me, the expanded "dark aelves" direction that GW is taking with DoK, wanderers and DK alliageance rules, and ID, along with the fact that none of the old high elves faction can function by themselves alone, makes me think that the next aelves release will be light aelves of Tyrion and therefore, they are slowly extinguishing the remaining factions.