(OOC: That's correct. The shimmering was flavour text--it used Pounce, and thanks to its superior reach, it didn't have to take any AoOs (not that an AoO is normally needed to Pounce, of course) )
*The creature snarls as Cade moves past his allies and darts a tentacle outwards to attack--but it doesn't aim for Cade! Instead, it takes an attack on Alton. Cade turns Alton hard to the side and avoids the blow. With the opening he was given, Cade makes a masterful blow at the crystalline creature and hits...thin air. Something about the shimmering light around the creature's crystalline body is quite odd.*
(OOC: I assume you'd want to use your Mounted Combat feat. It succeeded)
*Meanwhile, Tandi and Rillian prepare to attack if the creature decides to come all the way over to the other side to attack them. Instead, it makes another attack at Alton, and this time Cade can't protect his mount, so the dog takes a nasty blow. Then it backs away, provoking an attack from Cade that also seems to strike true but hits thin air, and then as it moves adjacent to the crystalline wall, there is a shimmering flash and it fades from view.*
(OOC: 12 Damage)