[MENTION=552]Creamsteak[/MENTION], if Grimjaw failed his Wisdom saving throw for Dent's Abjure Enemy, Grimjaw's speed should be 0. If that's the case, Grimjaw wouldn't be able to move during the surprise round.
EDIT: Of note, the frightened condition (PHB 290) would additionally mean Grimjaw has disadvantage on ability checks and attack rolls while the source of its fear is within line of sight, and Grimjaw couldn't willingly move closer to Dent.
That said, one out for you is that I haven't a clue whether Grimjaw failed or made his Wisdom save. Dent only knows that Grimjaw is afraid, which leds me to believe Dent's Abjure Enemy attempt was successful. I also am not privy to any help a reaver or the blue-skinned woman may have given Grimjaw (unlikely, since the reavers didn't get to act in the surprise round and the woman cast and moved? ).
Let me know, please. It'll change Dent's action for Round 1.