That fire spirit is so imba... 80 attack speed makes it a one point wonder, if you use that on the opposite team's carry they will not be able to last hit before you deny.
One point wonder my ass, it's the skill to max first. 75 dps for 16 seconds at level 7, 30 sec cd gg. Sunray is useless, skip.
Go offlane solo or mid, take dive first, max Spirits, make your enemy in lane cs =10 in 10 mins because they have -100 as. Can't get killed because u just fly away, 1400 range blink wow much skill. You need no mana , go straight meka into sheep win game. Combo is activate spirits, dive in, use spirits on ppl, go supernova win game. Alternatively, you may want to get dagger, blink into trees and still stun everyone with 10000000 range Supernova. Take sunray after maxing the two other skills cause it's a % based hp skill anyway. If you're not sure how to use you may skip it, the skill has been nerfed to hell and back (it used to slow progressively, making you basically unable to escape it, now it just damage). You may want to take 1 point to climb cliffs, but it's pretty risky anyway cause it cost you 6% hp per sec and u move really slow.
There are not a lot of reason to run him as support. He can't stun, he can't initiate, he can't even really zone out people at lower levels, and his spirits are weaker when you can't zone out the enemy solo for 16 secs with it, and instead have to spread the debuff. He's however hard to kill, and make life miserable for opposing lane solo. His spells also get amazing with some fast levels, and in particular he benefit from a fast 6. Then he can wreck teamfights, and his spirit does 1200 damage over 16 seconds. Dive is amazing already at 1, and leveling it fast give you an impossible to miss 1400 range 280 nuke, that's till not bad. You'll rarely want to use it as a nuke though, always as a tool to initiate your spirits->nova.
The hero is a bit too good right now imho. I expect a remake on sunray (yes, anotehr), and dive to go for 1100/1200/1300/1400 range , plus the as decrease on spirits to be worse , especially at earlier levels because it's seriously a bit too good right now.