I beg to differ with the docs that say
He is a great addition to any team.
Let's look at skill level 10 (why would anybody do this?).
With that six second cooldown we get:
* 460% every six seconds vs Set's 470% explosion every 1.4 seconds
* 2.3s stun every six seconds vs Set's 1.5s stun every 1.4 seconds
* ATK speed brought up to normal, until just before he needs to recharge
* The effect of FlameGuard that averages out to level 8
I really haven't noticed this rush to apply FlameGuard everywhere.