Hunter solo - Durendil vs Kael'thas Mythic (Sunstrider's Salvation)

This was ridiculously hard.
There is a timer in each phase after which waves and waves of infusers spawn and wipe you.
So bandages alone aren't enough.

First, you need a healing trinket. However, there is barely any on-use trinkets that heal in Dragonflight. I had the one from a quest of the Aberrus patch. I Suppose there is the Ampoule and the Darkmoon card, but I haven't tested them.
There is also the Voodoo totem, but it's hard to acquire dungeon trinkets.

You also need a ton of bandages for the Essence fonts, and I used a ring with the healing primordial stones from the Forbidden reach patch. I also used the heal from my pet on them.

Then there are the shields. I had to go for a 1-minute Tank trinket and either use Necrolord + 20% health buff or -30% or -40% reduction.
Also, be very careful not to activate an essence font during a shield or the boss won't heal.

I used dps CDs when the infusers spawned.

In phase 1, I made sure not to get the boss to phase 2 before the second infuser wave, and I waited until the 5 Occultists spawned.

During the first phase 2, I focused down Kael'thas. Occultists won't drop the Essence font if you kill them after they run out of energy, so I killed them before that.
This is because the second phase 1 is shorter than the first and you need the extra fonts.
Lastly, do not "kill" the phoenixes before they focus you or they won't die.

Then for the second phase 2, I had to hope for a crit (it didn't happen) or manage to get the boss right as the "wipe wave" spawns. As long as the boss gets to phase 2, you can kill adds then kill boss.