Strong Female Side Character Awakens - Chapter 143 - She Was Getting Sick This Time

A skilled but unfortunate modern-day assassin was killed in a freak accident. However, he soon found himself summoned to another world by an evil wizard, who had him possess the body of a boy as an experiment. After successfully planning the evil wizard’s downfall, he used the wizard’s body as a springboard to gain influence and power in his new world.

- Description from Novelupdates

300 years after becoming a Demon King, the war angel Ansel faced a serious problem during a certain expedition.

——His halo grew out once again.

Ansel picked an auspicious place that was definitely and absolutely unmanned, and while cursing, he simply and skillfully broke off the newly emerged angelic aperture.

This thing was growing out faster and faster!

When will his undercover mission end already?!

The demon realm was divided and ruled by three kings. Demon King Saros was forced to go on an expedition with his sworn enemy, Ansel.

One day, he noticed Ansel sneaking away from everyone.

Saros decisively followed him, and was shocked to find that his sworn enemy, another demon king of the demon realm, took off a horn headband and fake bat wings. As Ansel cursed up and down, Saros watched as he skillfully removed a cute halo from his head.

This irritable, easily angered guy who loves fighting; the type that was cute when he shuts up but could make even demons angered to the point of ascending to heaven the moment he opens his mouth…

..was actually an angel???

- Description from Novelupdates

Noah Brown had a gift for fighting. Unfortunately punching things didn't pay the bills, at least until he died and an Eldritch god found his soul. The encounter led him to a new world, summoned by bloody cultists, with nothing but the shirt on his back, and a strange item in his system menu.

[???] : A source of infinite potential.

Perhaps he'd finally get to put his gifts to good use.

Unable to control his mouth, Lin Jian Yin scared away eight previous girlfriends and six previous managers thanks to his poisonous words. Finally unable to stand it, he goes to a strange antique shop recommended by his friend. The shop supposedly has something that can help him.

Even though a Nintendo that plays cartridges is a bit outdated, and probably no one plays it anymore, isn’t it too exaggerated to place it in an antique shop to sell?

After returning home with a Nintendo, Lin Jian Yin inserts the cartridge that the owner sold to him at a huge discount. Only then does he discover that this is actually a simulation game. The female protagonist isn’t a cute loli, nor is she a mature woman. Rather, with her old lady hair and blue-white slippers, she is such a frightening woman that calling her a Taiwanese babe would seriously be insulting Taiwanese babes.

Gods! His mission is actually to help this woman marry a perfect prince! How is that possible!!!

Wait, as the main guy protagonist, Lin Jian Yin actually isn’t the prince. Then, then, who exactly is he… No, “what” exactly is he?