Jesse pulling a Big Damn Heroes moment in Shadowland/Love You To Death that should have been impossible. Sensing something bad was going to happen, he transcends the normal physical restraints of being a ghost and bugs her youngest stepbrother David until they finally go down there and save Suze, where she's been trapped under the rubble of part of the Missionary Academy's breezeway.
Suze, once and for all, proving that she's more than just a pretty face who happens to be quick with her fists when she gets one over on Marcus Beaumont in The Ninth Key/High Stakes. First of all, she refuses to go quietly to her death. Then she smashes open a huge aquarium with an office chair. Then, using one of the lights in the bottom of the tank, she electrocutes him. Even Jesse is impressed, and he hasn't been too happy with her of late.
"Sorry, but dead's never been my colour." SMASH.
Jesse beating the ghost of Felix Digeo, the guy who murdered him in his sleep, in a straight fight during the last part of Darkest Hour/Young Blood. He gets to do it again whilst alive near the end of Twilight/Heaven Sent, thanks to Suze's warning.
That's not all. The first fight can be justified in that Jesse has the advantage of his ghost form being quite a few years younger than Felix, whose ghost is a good ten or twenty years older than the twenty-year old Jesse. But the second time around, both of them are on an even keel- in fact, Felix even seems to have the advantage. And Jesse still beats him.
Suze barely needs to even think about Jesse, or be in the slightest bit of trouble, and he's there. To give this context, mediators can 'summon' certain spirits by concentrating very hard on them, or by doing so aloud. Yeah, Jesse is just that attuned to her presence.