Update Acc. : Alien Egg/Cosmic EggI think there is an evolving (Increases star of your aliens; Max Star 1 to 7 while there is an 8 star to limit break up to 5 copies; Oh you can limit break if you have the same character or you can use the based evolving material) and breeding system (If your aliens are max level you can breed ) that you can obtain buffs from other players to make your "Alien" powerful (Aoe/Single DPS, Debuffer, Buffer, Healer and Hybrid).
This might take a while to adjust specific skill if you want to make your aliens viable enough.