{Welsh Dragon Over Boost}
The jewel on the boosted gear glows red.
Afterward, he unleashes a profound crimson aura that begins to coalesce into elaborate crimson armor, which gradually takes the form of a majestic dragon.
The jewels from his gauntlet now adorned both arms, shoulders, and the middle of his torso.
On his back, there's an impressive set of rocket boosters that seem ready to propel him to incredible speeds.
Despite wasting time on his over-dramatic power-up, Riser appeared calm while waiting for the show to start.
"40 seconds left," Riser said, making Issei uneasy.
"This is the power of the Red Dragon Emperor, Balance Breaker, Boosted Gear Scale Mail. If you are scared, then go ahead and give up."
"Don't waste your time. You have 30 seconds remaining until I start attacking."
"Bastard"
Issei took his arms in close, condensing his demonic power into a ball, and then threw it at Riser.
"Take this"
Upon seeing the attack coming at him, Riser decided to take the hit.
BOOOOM!!!
The smoke filled the air as everyone watched in silence.
Laughter echoed through the smoke. "Is that the best you've got?"
The smoke clears and everyone sees a gaping hole in Riser's chest as he laughs.
"ONII-SAMA"
"Hey, keep it up, little dragon! You've got 25 seconds left before I start fighting back."
Issei decided to close the distance and unleash a barrage of punches on Riser, but Riser stood his ground, barely flinching as he absorbed each blow without budging from his initial spot.
"20 more seconds"
"Bastard"
Issei, feeling increasingly desperate, made a bold move by reaching into his gauntlet to pull out a cross. He placed the cross on Riser's head, causing his face to melt and eliciting a grunt from Riser.
Issei noticed that Riser was distracted, so he quickly took out a vial of holy water and poured it over Riser, causing him to stumble backward and fall onto his back.
"ONII-SAMA," Ravel screamed while crying
(First time writing a fighting scene. Let me know how it is.)