Double Demytha’s Double the fun! Block damage or cleanse the stun!
Unfortunately this is NOT affinity friendly natively: to be affinity friendly for spirit affinity you need to bring in a cleanser (doompriest/tuhanarak) or debuff blocker (on a 3 turn cooldown). To use a cleanser on UNM you need the Demytha’s to be at least 259.83 true speed. On NM all the DPS must be faster than 161.43.
To use a cleanser for Spirit affinity all DPS must be at least 165.16 speed.
The video has explicit instructions for managing either scenario as they each take some tweaking of skill timing.