Skill Seal is used by Light Izanami (and probably many future descends). It makes it so that you can't use your active skills, period. Yeah it fucks over Luci pretty hard.
When she activates it, it lasts for 10 turns, but as soon as it runs out she reactivates it so basically it turns your Siren into a 10 turn cooldown.
Meanwhile resistance stall is better since Minerva, Ceres, and Neptune are all bind immune, and Ceres can cleanse your entire team with her active.
Also they gave Luci auto heal rofl yeah that 1000 HP is gonna mean a lot