Awoken Horus is a necessity to have full Serket LS. Other than that his active is shit. Except when you need to remove decresed time to move orbs buff. I inherited Baldin on him. 50% shield and 2x to machine/dragons (RagnaD+Sakuya) for 2 turns. Not the best maybe, but I missed tans for anything better. Sakuya covers light/blue, clears binds and have an useful 20% gravity for Kali. The two RagnaD are the most important subs as they are killers, have awesome awakenings, high HP and an almost perfect active. Serket active is decent (35% shield with my subs). RCV is pretty bad even with the 2.25 coming from Serket's LS. That's why I'm using Supa Dupa RCV badge. HP is awesome. ATK is a poor 56.25x on a rainbow team. But killers helps a lot. Team has enough fingers to make it easy and fun. Serket can be paired pretty well with Yuna or RaD.