Your OC can either be mistook for a villain, or a villain

Legion titan: [his 20ft chassis hums with ai and his predator cannon's barrel spins] out numbered 8 to 1

Stinger: *He nervously adjusted the grip of his weapon* "Exactly, so surrender."

Legion: predator cannon locked on target [prepares to open fire]

Stinger: *He began spinning his spear at high speeds*

Wild Horn: *He mumbled something to Glasses in the back*

legion: "enemy hostiles detected" [he fires his predator cannon at 3,000 rounds per minute]

Stinger: *He abruptly dashed out of the way to a nearby tree, swinging off of it to another one*

Chain'n'toad: *He launched his Kusarigama at one of Legion's legs, planning on pulling to trip them up*

*Avery walked through the forrest, hearing them.*
Avery: Hello. Would you like some tea?

Death Gatling: *He fired a warning shot upwards* "Don't try and fool us “Hero Hunter”!"

Stinger: "You seem wise. Surrender, and there'll be no fighting."

Avery: More for me I guess. *lays down* Are you sure you have the right person? Most heroes are boring, so I don’t hunt them.

Stinger: *He briefly doubted himself before changing his mind* "If you're innocent then you'll have no trouble turning yourself in, right?"

Avery: Do you think they’d hear me out if I did turn myself in?

Stinger: "I thi-"

Death Gatling: "Quit stalling! Get up and surrender or we'll open fire!"

Avery: I was hoping that it didn’t come to this… *laying down still* I’ll pay for all hospital bills.

*one of them noticed a hole in the ground right below her head*

Death Gatling: "Fine!" *He immediately opened fire, using his machine gun*

Stinger: "Gatling!" *He clearly wasn't a fan of the aggressive tactics*

*A part of Avery’s hair grew and hardened, creating a shield. The other half went into the hole.*

Death Gatling: *He stopped his fire*
"Move in!"

Wild Horn: *He charged towards Avery, preparing to deliver a punch with his Pile Bison*

*Her hair launched out if the ground, grabbing Death Gatling and slamming him into Wild Horn.*

Avery: That’s for shooting at me. *smiles*

Death Gatling: "Open fire!"

Shooter: "Alright!" *They fired a barrage of arrows towards Avery, each one coated in poison*

Gun Gun: *He blasted twice with his two guns*

*She used Death Gatling to block the arrows, and used her hair to block the bullets*

Death Gatling: *He pulled out his bowie knife and sliced 2 arrows in half, but was hit by 3 others*

Chain'n'toad: *He launched his kusarigama at Death Gatling, pulling as hard as possible to snatch him out of Avery's grasp*

Smile Man: *Using his kendama, he tried crushing Avery*

*She used the momentum from Chain Toad’s pull to launch towards him and deliver a punch to his gut.*
Avery: Woo, you guys are more fun than I expected.

Chain'n'toad: *They collapsed, immobilised*

Death Gatling: "Don't give up..." *They passed out from the poison*

Wild Horn: *On the ground, they turned to Glasses who was being guarded by Stinger and Shooter before seemingly passing out*

Gun Gun: *They shot twice, aiming for the legs*

Smile Man: *He dashed in and used "World-Shattering Spin", the ball spinning insanely fast as it shot towards Avery*

*She let go of Death Gatling, instead using Wild Horn and Chain Toad as weapons and shields.*

Wild Horn: *He punched the ball, launching it away before blocking Chain'n'toad from the bullets then attempting to cut himself free from the hair*

Stinger: *He spun his spear in a helicopter motion to launch himself into the air before delivering a quick attack from behind*

Shooter and Glasses: *They briefly conversed from far away before turning back to the battle at hand*

Aquamarine: (imgflip.com/i/a2wz9r) Hi, who are you guys?

Death Gatling: *He fired a warning shot upwards* "Don't play dumb “Hero Hunter”!"

Stinger: "You seem wise. Surrender, and there'll be no fighting."

Aqua: I’m literally like… I think a teenager, I don’t remember.

Gun Gun: "Quit messing around!" *He drew both his guns and fired them simultaneously*

Aqua: woah there pal let’s take this back a notch. I’m not even in my dark world form

Death Gatling: "We'll calm down if you surrender, and if not... You can guess..."

Gun Gun: "You've got 5 seconds!"

Aqua: what happens if I surrender?

Death Gatling: "Life in maximum security prison."

Aqua: then no can do, I kinda have a life *grabs knife out of pocket, then stabs the ground to make a dark fountain*

Gun Gun: *He immediately shot with both guns aimed at Aqua's head*

Aqua: *seals fountain, they can see he dodged the bullet* can we calm down please? *is in 2nd form*

Death Gatling: *He suddenly switched to Death Shower, dramatically increases the gun's firing rate in hopes of catching Aqua off guard*

Aqua: what the? *uses the metal umbrella again*

Death Gatling: *He continued the fire, the umbrella denting significantly, the bullets about to pierce*

Chain'n'toad: *He launched his kusarigama at Aqua's feet, aiming to trip them*

Aqua: *jumps and uses the umbrella as a glider, to then kick the guys guns out of his hands* I won’t… fight…

(using a metal umbrella as a glider?)

Aqua: *fails miserably, it's a metal umbrella* well that didn't go how I planned... but my points still stands

Death Gatling: *His gun was smacked out of his grip, so he grabbed the knife by his thigh and slashed upwards at Aqua*

Shooter: *They fired a flurry of arrows at Aqua*

*uses the umbrella to block the arrows again, and jumps off death gatlings head*

Stinger:
"Tsk..." *He immediately lunged into the behind of Aqua, aiming to skewer them*

Glasses: *He stayed at a comfortable distance*

*A dozen arrows suddenly rained from from above as Shooter re-equipped their arrows*

( btw I'm not that well versed in Deltarune's power system :P )

Aqua: *grabs pen and makes an iron umbrella* know this is closer to a fair fight *copies Jevil's face*

Shooter: "Be careful! This guy seems dangerous!" *Poison leaked from the arrows down the umbrella*

Chain'n'toad: "Clearly stupid if they try to beat all of us...." *They launched their kusarigama at Aqua's chest*

Aqua: seriously? I just want to get to school! *makes a ReviveMint*

Aqua: *muttering* why couldn't they just have magic attacks?

Chain'n'toad: *The kusarigama slammed into Aqua*

Gun Gun: *He shot the ReviveMint out of Aqua's hand* "Don't let them get a moment's rest!"

Smile Man: *His kendama's giant ball was launched towards Aqua*

(images included for visual aid)

Aqua: *jumps up and eats the ReviveMint, making the weapon disappear from his chest* you know, you’re only helping me get stronger by attacking me *points to TP bar on pen* the more of this I have, the more stuff I can make *makes a shield, just before the ball hits him*

Gun Gun: "You haven't launched a single attack. You can't stay on the defense forever." *He reloaded*

Shooter: *He launched a single arrow at Aqua's chest*

Stinger: *He charged in* "Fight back!"

Smile Man + Chain'n'toad: *They retracted their weapons*

Aqua: … *weaves, dodges, and makes more defensive things as the attacks come, obviously refusing to fight*

Death Gatling: "Move!" *He yelled*

*The other heroes quickly got out of the way, and he began shooting out of his intimidating gun, the stray bullets tearing down trees*

Aqua: *starts running towards them, as they draw something, dodging to his best abilities*