Useing Holy Spirit technically is a potency gain but if you use total Eclipse and any of them cause a direct/critical hit there potency suprases Holy Spirit. You also have a higher chance of criting them hitting multiple mobs than just the one. Really useing a 2x flash + circle should be enough of a lead to maintain aggro whiel you spam eclipse. I had very little problams in dungeons doing this. Circle does give enimity and is off GCD. if you need to hit flash every 5 eclipses to top ur hate off but most mobs should be dead before you hit eclipse 10+ times. unless ur DPS are just blah.