@NazethNecrotyr Seal of Command works great on aoe abilities like Divine Storm and Whirlwind. Each target hit, procs the seal splash on 3 more targets. You could very easily make a build around Divine Storm and Whirlwind, however your single target dps would suffer.
You could make a talent preset build for boss fights, and run that one epic RE that makes seal of command hit 30% more but only does single target then. And focus on the single target abilities you listed off for boss fights.