Well, I suppose you'd better show this Yellowjacket that gettin' smacked about by a mad kraken wasn't a waste of time after all! Just take aim at Latool Ja and fire off a Water Cannon.
This NPC is found in multiple locations. The map below shows where the NPC is first encountered.
Martyn wearing "normal" clothes during Scream Blue Murder
Martyn wearing his Celestium preformance clothes