Who to merge?

I got 2 Halloween Kageros and Sigurds. Kagero is +res/-atk and +spd/-def. -atk hurts but I have a stronger glacies special. +spd is useless and -def hurts her bulk. Which one should I keep? I plan on merging.

As for Sigurd, I have +spd/-atk and +atk/-def +spd gets a decent amount of doubles with buffs and survives well. Is +atk worth sacrificing his bulk for? Should I fodder the other one because close defense is a good skill.