General Disclaimer: I don't own the Marvel Cinematic Universe. I also don't own the Buffyverse or any characters in either one. These are someone else's sandboxes. I'm just playing around in them a little.
On the road to Coulson.....
“Phil, you have to.” Fury whispered to the dying agent.
“It's been years.” Phil Coulson whispered. “I don't like going back to that.”
“It doesn't matter. If you don't you will die.” Fury told him. “That's an order Agent.”
Phil nodded and pressed a button on his watch that let out a loud 'Awooga' sound. After a moment, a ripple of energy extended from the watch. What was once a tailored suit, turned into a purple and black jumpsuit and where there was once a normal hand there was a white gloved, four fingered hand instead.
The ripple extended over his body and he was transformed into a living, and fully healed cartoon clown.
“What did you just do?” Agent Maria Hill demanded as the transformed and fully healed Phil Coulson opened his eyes and started giggling.
“This is over your clearance level.” Fury told her as whatever Phil was pressed his watch again, causing the transformation to happen in reverse only...
“I feel different.” Phil said as he adjusted his tie.
“You look different too.” Fury told him. “Seems there was a slight side effect.” He grinned. “Looks like we're going to have to update your ID photo and age.”
“I'm a teenager again aren't I?” Phil sighed. “We suspected this might happen if the damage was bad enough.”
“What happened?” Maria demanded.
“Phil has his own codename. Designation: Slapstick.” Fury told her.
“He turned into a cartoon clown?” Maria asked. “Why haven't we used him before?”
“I'm more than a little unstable when I'm like that.” Phil admitted. “Not to mention I'm lacking in certain aspects I'd rather not be made public. I take it we're going with plan C then sir?”
“Yeah. Cards are still in the locker right?” Fury asked.
“Yes. Use the blue box. They're the extras.” Phil told him.
Fury nodded before walking off. He paused at the doorframe. “Not a word about this Hill. Phil, stay put.”
Maria was about to protest but Phil simply said “Yes sir.”
Maria and turned to look at the much younger Phil Coulson. “How are you remotely okay with this?”
“Compared to my life before I became a member of SHIELD? Today's a cakewalk.” Phil told her with a grin. “If you don't mind, I'm going to go hide until this particular crisis is over.”
“You are definitely a strange guy Phil.” Maria told him.
“Strange is my middle name.” Phil grinned. “Though once upon a time and a reality away it was Lavelle.”