Prince Kenneth is the main antagonist of the final quarter of Grimm's fourth season. Following King Frederick loosing patience in Viktor's lack of progress, in the search for his granddaughter Diana, he chose Kenneth to take over the operations in Portland.
Arriving in Portland, he first interrogated Adalind Schade, learning that Nick was once again a Grimm, and that Juliette was now a Hexenbiest, he then discovered she was pregnant again, and enquired who the father was. Adalind lied that it was Viktor. Upon his apparent agent Sam Damerov arriving to give him the progress on the search for Kelly Burkhardt and Diana. Kenneth immediately realized that Sam was in fact secretly working for Sean, and violently beat him to the ground, then told Adalind that Viktor was incapable of having children so she better guess a better father.
He then forced Sam to call Renard so they would meet. Before having Sam brutally executed, arriving he confronted Sean. And unlike his predecessors didn't even bother trying to negotiate instead he simply attacked him. The fight broke out between them, although Sean was super humanly strong, Kenneth managed to hold his own. Half way through the fight however, Sean's condition began acting up, weakening him enough for Kenneth to beat him. He then mockingly told him, he worked his way or he would die.
Later Kenneth realized that Nick must have a way of communicating with Kelly, and began to formulate a plan. Returning Adalind revealed Juliette was after her, but Kenneth found this more amusing, and began planning how to use this to his advantage.
Discovering Juliette had been arrested, Kenneth decided this could be used to his advantage and planned to corrupt her, as she knew Nick and his mother much better than all of them, and thus might be the key to finding Diana. Adalind was originally sceptical, but then Kenneth enquired again about who the father of her child was, before smugly telling her he knew it was Nick. He then revealed that he planned to sacrifice Adalind to Juliette, and let Juliette know Adalind was carrying Nick's child.
Later he had Juliette bailed out, and went to talk to her. He revealed the truth about Adalind's baby, and began to manipulate her. At first Juliette didn't believe him and left, but Kenneth told her where she could meet him. After Juliette found out it was true and Adalind was carrying Nick's child, she went back to Kenneth. He manipulated her, by convincing her Nick no longer cared about her and told her his plan to get Kelly. Filling her with promises of what the family could offer, and appealing her new found selfishness, he convinced Juliette to help him. Having her send Kelly a message, that Nick was in danger and needed her.
Arriving at the house, the two went over the area plan, Kenneth formed a perfect ambush to beat the experienced Grimm and take the child. While waiting he also sex with Juliette, in Nick's own bed. The next day, he had his forces move in a kill the all the neighbours, taking there houses to use as bases. Filling them with his troops, they waited for Kelly to arrive.
Eventually she did, Kenneth had her ambushed by over a dozen Verrat agents, dragged outside where he personally murdered her. Then to add insult to injury, he had her head cut off and left it in a box in Nick's home, for him to find. Taking Diana, he went with Juliette to see the king.
Arriving he dropped Diana off with her grandfather, and told him that Juliette had helped. However King Frederick was less happy over the fact Nick was still operating. When Nick arrived back in his home, Kenneth sent in his army to kill Nick. But they escaped, he went back to Portland to take over operations to kill Nick. However Nick was one step ahead of him, and had him taken by the police.
Wu dropped Kenneth off in an abandoned warehouse, where Nick confronted him. Still smug, Kenneth mocked Nick over killing his mother. However the enraged Nick took him on, although skilled Kenneth proved no match for Nick's powers, armed with his Vambrace, Nick killed Kenneth, avenging his mother.