I went 1/20, always had problems with dealing with Meteors on phase 2 (5%) and Dynamo. Either BLMs complainining they can't target meteors or mages just can't find the sweet spots for dynamo.

it can suck when Nael decides to Dynamo while the BLMs were running to position to intercept meteors.

at 5% after he teleported, have all your WHMs, BLMs, BRDs focus on debris (this is extremely crucial), 2 DDs focus on Nael. The golems are weak and can be slept. Focus on killing meteors until Nael comes down.

when he comes down, he might or might not follow up with his combo (2x close circle AOE + Dynamo). So be very careful when approaching him, let him come to you (you are standing at the same corner as before anyway). And resume the fight just like start of phase 2.

if he does pull out his combo and knock some of your guys out, then burn your 15min ability or whatever to speed kill him / stay alive. He should be at around 5%+ hp anyway, burn him out and you should win.