The end game can be quite the grind. If Sera can weather all of Ret's tricks, I believe she has a slight advantage during the end game.

The classic fight of good vs evil! Sera is very predictable, Ret Talus doesn't need to be afraid of surprise plays and can afford to use his ability to the fullest. Renewed Hope is Sera's only trick, you have a be aware of as FK player. On the other hand, Ret's deck is full of combos and tricks. What got me more than once is a 7+ attack Undead Warrior in Sera's face. A 2 life or even 3 life blocker can get removed with purging a Cultist. With the Help of Blood Summon Warriors can pop up in unexpected places. For Sera it's essential to make good use of her events esp Holy Judgement. Combine Holy Judgement with the other events and Priest's Healing ability to extend it. Undead Carriers are Ret's endgame tool, their disadvantage of not getting Magic for destroying units does not matter anymore. Very important to know is you can attack your own Units as well, healing your Carriers or turning another wounded Unit in a healthy Carrier. It also allows you to attack twice from one side. I feel Sera has a slight edge in the endgame due to the strong stats of the Knights and their Protect ability. The endgame is quite interesting here. Sera has access to one of the best Commons in the game with the Citadel Knight and she keeps bringing them back.