Ben 10: Alien Force, Season 3

Devin Levin:
Ragnarok?

Grandpa Max:
In the Null Void, where he belongs. You just, rest easy. You're gonna be okay.

Devin Levin:
(groans) We both know that's not true pal. Still... it's not a bad way to go. Saving the world.

Grandpa Max:
Devin, no, no stay with me!

Devin Levin:
[last and final words] I'll always be with you, Max. Tell my wife and son I love them. [then dies]

Grandpa Max:
I will, old friend. You have my word. I promise they'll be proud. [End of flashback] We tried to find Ragnarok's ship. But it disappeared when he was sucked into the Null Void.

Ben Tennyson:
But what does Kevin want with him?

Grandpa Max:
My partner's name was Devin Levin. Ragnarok is the monster who murdered Kevin's father.