I think the only actual good uses are a mch(Only at the start of a fight) and your own luminous aether. Mch pops a lot of cooldowns at the start of fights, especially on a boss where he'll pop everything to maximize wildfire.

Tanks at the start of a fight, ninjas in general(Should just about always get his ninjutsu) and smn/schs with no aether stacks are 'ok' uses. But I'd still probably try to avoid using the spear in these situations and shuffle/rr if I could.