One of the big things with Kjalnar is that you need millisecond reaction times, especially if you're melee tanking him. I'd suggest really studying the fight videos so you can recognize the animations because you need to react right away.

Kjalnar's Abyss attack needs to be dodged, full stop. I'm the kind of tank who likes to plant and just take hits, but Abyss is a major problem. The biggest issue there is that there's very little notification that it's coming, particularly if you're in melee range. As soon as he starts the Abyss animation, dodge left or right. It's something like him lifting his sword up in a giant circle.

You can also try putting on Slippery as a CP star to auto-break free from the grasp. I didn't, but that's because I found out that I almost bash-weave when I'm tanking when Turning Tide came out (I was almost always proccing it since I reflexively bash so much), but because of that I also was very quick on the break free. Again, the grasp needs millisecond reaction times.

Another thing - you should never be rezzing. That's the DPS's job.