Technically everyone on Nilou team will trigger some blooms so em weapon is not bad option.
Comparison with different weapons and with double HP and HP + EM set. This is theorycrafter who is Nilou main channel so there should be more good videos on her and teams she runs with. Personally I gave her Xiphos since my other EM swords are taken by characters I use and started to build Collei just for her team.