Uncle Jay is the main ghost in this episode. He died of a heart attack just a few hours before he could give his nephew Liam, something important. Uncle Jay misses his nephew and misses being alive. When he meets Axel he realizes that his unfinished business could be corrected and that Liam could receive what Uncle Jay wanted to give him so he can finally move on.

When voicing him you should sound sad, but cautiously optimistic. Uncle Jay has a lot of spark for a dead guy. Keep in mind that this is the kind of old man that can take a pun about his own death and make one in return.
Axel: Come on, there's no need to be in such low spirits.
Uncle Jay: You honestly can't blame me for being sad young man. At least I'm not soulless. (chuckles)