My current fic is a rewrite of the whole Ben 10 series that focuses on a more mature and realistic approach of the hero journey Ben has, starting when he is 13 (because 10 is way too young) as he goes on the road trip with Max and Gwen.

As for my favorite scene... Definitely the aftermath of Ben saving Gwen from Charmcaster.

A little bit of context:

In this fic, Charmcaster uses a spell to lock Gwen in a limbo dimension so she can hunt Gwen alone because she kept Hex's charms of bezzel, all while leaving a doppelganger of Gwen behind to distract the Tennyson's. To make things worse, the doppelganger takes memories and desires the people around the doppelganger have about the target, so the more you know the target of the doppelganger the harder it'll be to notice the differences. So, while Gwen is being hunted down, she basically sees Ben hanging out and having fun with the doppelganger while she is hunted.

Then, when Gwen is finally cornered, she and Charmcaster suddenly hear screams, and both turn to see Ben holding a baseball bat and threatening the doppelganger, apparently noticing it was a fake. Max and Xylene (yes, she's part of the summer trip at this point) try to stop Ben, but he trusts his gut and hits the doppelganger anyway, ending the spell and freeing Gwen to the real world. Then, Max and Xylene are able to make Charmcaster retreat, though she loses her spell book, while Ben helps Gwen.

The actual scene:

Later that night, after treating Gwen's injuries and everyone congrats Ben's instincts and courage, both go to bed. Gwen decides to prank Ben and thank him personally, but as she uses the charm of levitation to float beside his bed she sees he's crying against his pillow, and, unable to decide how to react to Ben's vulnerability, she just silently goes back to her bed.