Your video is the size of a postage stamp, so I can't really look at it properly. If you upload it to youtube and post a link, it will be easier to analyze.
If no one gains any tm, that means it's all the same turn, and he is just using his up to 3 attacks. If you see your characters suddenly have more tm in between, that means he is on a new turn, as tm bars only update when someone takes a turn. Whether the boss is simply that fast or whether one of his abilities grants him tm, I cannot say.
My current speeds are 289 Bast, 226 HK, 178 Canderous, 208 Carth, 180 Juhani, and the borrowed Revan appears to be at 148 with no mods. I am able to beat this without too much sweat, though my characters are geared more than yours.
It may be prudent to gear everyone except Juhani more anyway, even with swapping mods, as not only do you face harder tiers ahead, but also there's a power gate to get Malak. DRevan has limited use without Malak so you will need to get those other four to g12 eventually anyway.