It’s got some good match ups, I’ve been using it mostly just for the novelty of it. Just go ES first, then spam distraction. Don’t use RC unless it’ll net you the kill guaranteed. If Grylenken is going to go down for sure, use Immobilize to make sure they can’t escape your next dino. Even if they are immune to the stun, that 2 turn pin can be priceless.
I do think it needs higher hp. Phorusaura is kinda broken in comparison since it has in essence an unblockable 2800 rampage plus sidestep, and it can run out to stun it’s way back in. 3600 HP and 1400 attack with that kit is nuts. If it had high health and low attack or it was a glass cannon, that’d be fine. But right now it’s out of whack. Grylenken needs some love for sure to measure up.