User blog comment:Mich, Michele & Kuhla/Future Units Preview/@comment-27268294-20160115122149/@comment-26336535-20160117163818

Ah wait, I misunderstood what you were saying. Yes, I'm pretty sure Orna could offer more damage than another 50% crit damage buff. However, there's a rather low chance of the Critical Spark happening, and you already really only spark about half of your hits (probably less), so unless you're amazing at sparking, a Crit Damage buffer might be the way to go instead of Orna.