Well, since in this raid, sephuz can be proc in several boss fights (High Command, Eonar, Portal Keeper, Aggramar), even though there are bosses that can be proc more frequently like eonar, High Command or portal keeper, and others like aggramar that only can be proc in certain phases (+ if your raid allows you to do it).

Note: talking about hc or mythic when it releases

I personally haven't tried sephuz yet in this raid, but maybe i'll do a test next week. Personally i think maybe it would be worth to go in High Command and Aggramar, since it's pretty easy to get the proc by interrupting a pyro of a add, or ccing an elemental with banish since it algos has a duration of 30s (but you should tell your raid to let you cc the last add to bring to the boss). What do you think about the other bosses? Any other ideas of procquing sephuz (not includng racials like belf silence/tauren stun)?

I know there are also a couple bosses like argus that you can also proc it, but since it's only doable in 1 phase, i'm not including it, since imo it'll not be worth.