Mettaton is a robot from the game Undertale, He plays Meeting Earth-chan in this video, and dies to Jupiter-chan, then appears to have determination, as he re-appears and comes back to be with Earth-chan.
Mettaton is just like he is in Undertale, Promoting his brand and acting fabulous, Mettaton's only problem is he does not know when to stop talking and let other characters talk, this causes a problem with him thinking other lines from characters that are not named "You" are his lines.
Mettaton re-appears in Anime Chara & Friends play games, He is a major character, Helping the others get through the games, In the Ugandan Knuckles game however, Jupiter-chan from Meeting Earth-chan helps the others.
He sounds a bit like Ursula from The Little Mermaid in a few parts of his debut video, However, Mettaton sounds normal in other parts.
Mettaton's first item he mentions in his debut video is a Glamburger, which is because Anime Chara didn't provide his voice actor, TylerAK412, with a list of items.
He gets killed by Jupiter-chan BECAUSE he wanted to be with Earth-chan, causing her to act like a yandere and kill Mettaton's friends, and then he still rejected Jupiter-chan, so Jupiter-chan kills him.
It is implied MTT Resort exists within Anime Chara's multiverse, As Mettaton mentions it in his debut video.
Mettaton being helpful was because he was not the main character of that episode, so Anime Chara suggested he give tips to the rest of the crew, However, Jupiter-chan and Alphys also had this role.