So I tried this in SK with Hazeus and it didn't work at all. Specifically, both a) pulling with bruscos while low hp and b) pulling, hitting all mobs with Largos 2x and then being low hp worked for like 1 nuke.
Anyway I'm curious if anyone who has actually gotten this to work can speak up. In hindsight its looking like it was Zanderr's snare that was just higher aggro than my nukes. Zanderr claims it worked at 30+ so maybe thats it.
edit: found my own answer:
http://www.project1999.org/forums/sh...ad.php?t=65750
TL;DR: Seems Low HP aggro only functions on mobs over L20.