I was wondering if I could get him before the coming gear/corruption/belt buffs. As a hunter, phase is a big issue.
I went for the simplest strategy possible, frontrunning the RNG then going for full dps.
I did have to use a tank trinket for my survival, a healing trinket for adds, and the healing gem in Cyrce's circlet.
I need to get lucky on the first spirits, having a proc before they died. You can afford 2 spirits deaths.
For the second set you have more time to proc.
And each time you need to 2 procs to get the adds to full health. I could use bandages on the second set to help.
If I didn't get lucky, I just reset.
On the third set I used the healing trinket.
To survive longer I used turtle on the first debuff in phase 2 to survive until the end.
Then it was simply full dps before he flew away again.
With more gear, the strat will be full dps gear and kill him before the first flight.