What gripes me about all the underdark fights is the depth that they deviated from the monster manuals. Just giving them an thematic attack like a cleave or something ontop of the charge I feel would be fine. But their jump also does aoe *pass test or damage and prone* and they have multiattack.

Right now they got extra:
-more movement
-Multi attack
-Aoe jump (which also crosses insane distances) thst does aoe attack upon landing
-shockwave. Not sure what it is (aoe cleave maybe?) But i saw it a few times.
-charge not requiring 10 feet of movement before they can use it.

Their movement ranges that they gain by using their charge and jump make them so insanely fast I cant fathom they put it in the game and went 'yes. This is a perfectly balanced fight'

Dropping everything but the charge, maybe give them a special sweep attack (if shockwave already is that, let them keep that) and call it a day. The fight would still be a very big challenge not to lose anyone without requiring the player to burn all their abilities in 1 fight.