Garou vs. Royal Ripper and Bug God

Garou vs. Royal Ripper and Bug God was the battle between Garou and two Demon-level members of the Monster Association: Royal Ripper and Bug God.

Prelude
While he's talking with Tareo, Bug God and Royal Ripper approach Garou and question his monstrosity. They tell him to kill Tareo. He refuses, and Royal Ripper charges at them.

Battle
Royal Ripper attempts to kill Tareo himself, but Garou catches his blade. Garou swings Royal Ripper midair, and strikes the monster with a left kick to his stomach. Royal Ripper is sent flying, but he uses his blade arms to stop his fall, spins his body multiple times, and twists his arms back into place. Tareo runs away, and Royal ripper officially declares Garou as their enemy.

Garou takes a stance, and prepares to fight, while Royal Ripper and Bug God charge the hero hunter. Garou punches Bug God in the chest, but Garou is unable to damage Bug God, hurting his hand in the process. Royal Ripper swings his arm blades, but Garou manages to intercept all the blows. He then expertly redirects the blade strikes to Bug God. Bug God is relatively unaffected, and punches Garou down into the cement. He then punches Garou upward into some electric lines. Garou is able to resist the electrical current, and swings back to Royal Ripper and Bug God.

As the fight draws out, Garou concludes that the two monsters are nowhere near the level of Bang, and that he can beat them. Likewise, Bug God and Royal Ripper admit that Garou has impressive abilities, so they decide not to hold back. Garou mocks the two monsters, spitting a tooth out of his mouth while declaring he's seen through all of their moves and they won't hit him again.

However, the battle is interrupted by Sludge Jellyfish, who captured Tareo. Bug God asks Sludge Jellyfish what he's doing here, and the monster replies and says he's waited for this moment to exact vengeance on Garou for punching him. Garou yells at Sludge Jellyfish to let Tareo go, but Garou lets his guard down, allowing for Royal Ripper and Bug God to take advantage.

Royal Ripper slashes Garou across the back, and Bug God slams Garou in the chest. Royal Ripper continues slashing erratically at Garou even when he's already down, letting his sadistic instincts take over, until Bug God stops him, reminding Royal Ripper they aren't supposed to kill him. Royal Ripper argues that he's already dead, and it was way too late to stop him. The monster sadistically looks at Tareo to bring him back with them, saying they will be good friends. The three monsters leave with Tareo while Garou is left for dead.

Aftermath
Tareo is brought to the Monster Association headquarters as an extra hostage and so Royal Ripper can torture him. Meanwhile, Garou manages to get back up from his massive beating. When he wakes up, he is still in pain and remembers what happened to Tareo. He also notices that his shirt has completely adhered to his body, signifying the start of his transformation into a monster.

Trivia

 * In the webcomic, Royal Ripper, Bug God, and Senior Centipede (who was still alive due to Elder Centipede being manga-exclusive) were sent by the Monster Association to save Garou from the incursion perpetrated against him by Bang and Bomb. After Garou was appointed by the Association to kill 100 humans to prove his monster nature, Bug God, Royal Ripper, and Senior Centipede followed the human monster to watch over his actions; when they discovered that Garou didn't want to abandon his humanity and was also defending a child, Tareo, they attacked him and tried to kill the child. The battle is not shown, but during this battle, Senior Centipede was killed, Royal Ripper and Bug God were injured, and Garou was defeated, just as in the manga.