For packs:

Shield lob > Flash > Fast Blade > Savage Blade > Flash > Rage of Halone > Full combo. If you are having trouble one trick you can do is FB the first target, SB the second, Halone the third, etc. I haven't had any issues.

As for Qarn the Golem doesn't have an enmity reset, he just targets a random person every now and then. Since we don't have AOE enmity generation you have to pick your enmity battles. Provoke > Fast Blade stragglers, weave flash between Halone combos, etc.