Wynnexcavation Site D Boss Stuck

So i have been trying to kill the last form of Amadel for around an hour, but everytime i enter it uses some kind of attack that flings him forwards and every single time he's got stuck inside of the blocks and slowly rises, The thing is its behind the barriers so i cannot attack him anymore all i can do is /kill and i have done that already 3 times over i just don't know what to do... as i am typing this i am inside the boss arena and its gone out of view i can no longer see him anymore.

Could not add an image/link since i do not have enough posts yet sorry.

 

Firstly, you don't have to /kill to reset it, /class will despawn all the mobs in the arena so when you rejoin he'll respawn in the center again. Secondly, if you're using any spells that do a lot of knockback, like uppercut or arrow shield (and assuming he doesn't have CCI), try to avoid those ones, as they make it a lot easier for bosses to get stuck in walls.
Also, if you want, you could try getting a high-level player to help you kill the boss quicker to avoid it getting stuck in a wall, although you still have to do some (I think 30%ish) of the damage to get the drop when it dies.