Meaning of “levechi”(レベチ)

It means “It’s not the same level.” or “It’s not in the same league.”
“levechi” is an abbreviation of “level chigai”(レベル違い).
“level” means “level”.
“chigai” means “difference”.
This word is mainly used as good meaning.
And it’s also almost gyarugo(meaning young lady often use).

Yes, Japanese like games so we use some words which is related to game like murige.

Example Conversation

A: Kanna Hashimoto is quite pretty, right?
B: Yeah, she is levechi.

A: 橋本環奈ってまじでかわいいよね。
B: ね。あれはレベチっしょ。