"This is an awful idea for most people Oz."
"I don't know what you mean mister Yin."
"I see you smirking behind your mug you bit-" The pad beneath Chris launches him into the forest after his classmates.
"Convenient timing. Now we see this years team formation." Ozpin and Glynda watch through the hidden cameras around the forest.
"Of course I had to get cut off before I could finish my sentence." Now in the air, he waits until the most opportune moment to use a grappling hook arrow to slow his momentum and land properly.
'Now, I just need to avoid everyone until they partner up. I don't want any of the teams that would form without me here to change. Especially RWBY, they grow so much as a group that I don't know would replicate without those specific teammates.'
Using his stealth, he hides from every Grimm he comes across and quickly slaughters it. Every Grimm in this forest is just not at his level.
"This is boring. Hope you're happy watching little children frolicking through the forest with their murder weapons."
...
"Did he just look at the camera?"
"He knew it was there Glynda. I don't know how, but he did."
"It was easy to find for anyone paying attention Oz. You didn't camouflage the cameras."
...
"Ozpin. You didn't camouflage the cameras?" Glynda was deathly calm, a sign of impending doom. Ozpin just sips his mug.
"He's the only one who found them. Just keep watching, miss Rose has paired with miss Schnee, and miss Belladonna with miss Xiao-Long."
"What does watching us even serve? If a tough Grimm attacks before anyone could come, it could turn you into a kebab." shaking his head, he moves on to find the relic resting place set out for the exam.
He finds it shortly after, and lies in wait until the last of Team RWBY and Team JNPR arrive. It was time for his climatic entrance!
"I have... arrived!"
"Who's that!" Nora wonders.
"Big bro!" Ruby shouts.
"... he's your brother?" Weiss looks to see.
"Hey... cousin." Yang reluctantly sighs.
Ren, Pyrrha, Jaune, and Blake say nothing, focusing on the Grimm.
"Hey guys? That thing isn't stopping!" Jaune observes.
"Shall we do this the easy or hard way?"
...
"What's the hard way?" Blake questions.
"You all look badass but take a while to finish them off."
"What's the easy way?!" Jaune shouts.
"You throw me at them."
...
"You're crazy. I LIKE THAT!" Nora picks Chris up and chucks him at the scorpion Grimm, where he promptly slices the stinger off. It roars in pain, but Nora follows up by planting it face first in the dirt with an overhead hammer bash.
"Finish him!"
Ren nods and shoves his weapon's knives into its eye sockets, causing it to disappear.
"Fatality."
The Giant Nevermore which brought Ruby and Weiss to the relics circled back and fired it's spikes at the group.
"Run."
"Run and live? Good idea." Jaune jokes, scared.
The group runs away, and when the Nevermore got too close to the ground it was brought down and swiftly executed with teamwork and the power of friendship.
...
Did I say friendship? I meant six high tech mecha-shift weapons, a family heirloom, and Ren's basic gun dagger... thing. Chris didn't bring out any of his weapons except a Grimm Bone Knife.
Time skip
"... I'm proud to announce Ruby Rose, Weiss Schnee, Blake Belladonna, and Yang Xiao-Long now form Team RWBY, led by Ruby Rose." Polite applause and Ruby looks confused, with Weiss looking a little angry but almost looking away.
'Guess she's thinking of my words from earlier, she's not going to get everything she wants here.'
Weiss's eyes find Chris and he nods with a smile. She looks a little relieved at having a friendly face in the audience.
"Next, I present Jaune Arc, Nora Valkyrie, Pyrrha Nikos, and Lie Ren as Team JNPR. The leader of this team is Jaune Arc." Jaune mouths leader to himself and falls when Pyrrha gives him a light punch to the shoulder in congratulations, earning a little laughter from the audience.
"I'm sure Team RWBY and Team JNPR are wondering about the ninth person from the exam not being assigned to one of their teams, so would mister Yin please step up on the stage?"
"Oh right, this where you try to sell the mystique of "letting me choose the team" I'll be with?"
"... you had to ruin it didn't you?" Ozpin sighs and the audience laughs loud at the flat out dismissal Chris shows.
"You should already know my choice anyway. Team RWBY. If you use my last name initial you even get to keep the color shtick."
"That's what I planned to do anyway. C doesn't work anywhere in the acronym."
"Glad we agree. Gotta keep my little sis and cousin safe anyway." ruffling Ruby's hair and flashing Yang a smile. Yang grits her teeth a little but stays smiling for the public. Totallyyyyyyyyy no sexual tension building there. Probably.
...
I hope?