I can make a change (a steven universe time travel fic)

the query

the sky was clear as the sun shone brightly down on steven, uni and amethyst

"okay, so what's the first thing you wanna learn?"

"the spiky ball thing and flying!"
uni pauses

"so, something easy- your shield"

steven sulks he wanted to get to the good stuff first not
the weak stuff

"try.. swiping your arm over like.. this..?"

uni demonstrates the action with little difficulty steven tries to mimics the action to no avail amethyst laughs at Uni's failed attempt at teaching, her hair shifting as her head moves

"uni, you're gonna wanna teach harder than that"

As she continues laughing
uni gets an idea

"okay, then amethyst could you help me demonstrate for steven?"

she stops her laughing
"PFT- yeah sure."

amethyst jumps down the steps and lands in front of steven
Uni grips her shoulders hoisting her up above his head placing her in front of steven taking a few steps back afterwards.

"okay, steven.. imagine im a..monster.. and i'm coming over there to attack amethyst"

"you don't look like a monster.."

uni sighs and shape shifts his fingers into claws

"AAhhh! are you gonna get covered in spikes???"

"what? no- i can do this just fine.."

uni barely suppresses the thought of him turning into a cat monster but shakes the thought. he'd almost forgot how far he'd gone..
he steps back a couple more feet

"okay steven when i way you're going to jump in front of amethyst to protect her and that should summon your shield?"

"haha, okay uni" amethyst jokes "just be careful you don't poof me
alright?"

uni pauses clutching his fists "amethyst don't joke about.. that please.."

she looks back at him shocked

" wait I don't..do I..?"

"no! i mean, yes- whatever let's just get this over with"

Uni charges at amethyst the pitter-patter of his flip flops pounding on the bare tile floor. she looks at him, fearfully as his body comes barreling at her full force. steven jumps in front of amethyst to block uni with his shield
and just as uni is about to swipe at them he hears a clang..
Yes! Yes steven did it! He summoned his..

"Oh, C'mon!"

His bubble..

Uni shape-shifts his hands back into fingers rubbing his wrists a bit

"That's okay, at least you have your bubble under control.."

"Yeah, he does have his bubble under control but you looked just about ready to shatter me! What's wrong with you dude??"

She stared angrily at uni but conveyed a voice of concern. she was scared of him and was still skeptical of his sudden appearance.

"Amethyst i-"

"But! I don't want my bubble!"

Steven shouts over Uni completely disregarding his last thought.

"i don't want my bubble!"
He repeated as the bubble went down

"i want my shield!"

He looked at uni desperately and uni contemplated his next approach.. What had made him summon his shield the first time?