「でも、人間ご飯食べなかったり寝なかったりすると死んじゃうけど、どんだけセックスしなくても死なないんだよね。不思議だね性欲。確かに子孫残すのには必要だけど、なんか『三大』ってカテゴライズに入ってるの違和感ない？四天王最強の男は実は無能者だった的なアレじゃない？」(source)
I know 的 is usually used after a noun and turn the noun into an adjective. But it’s the first time I’ve seen it used after a sentence. So how should I understand this usage of 的? How is different from “noun+的”? And what does アレ mean in this context?
It is probably easier to parse if written as
「四天王最強の男は実は無能者だった」的なアレじゃない？
「～的な」means "(something that is/feels) like something else". It is something of a different usage than noun+的, but semantically similar, sharing the meaning「…のような」. In this usage 「的な」can be preceded by a number of endings, functioning like a quotation marker.
「青春だった的な歌」: a song about bygone youth
「きれいになった的な話」：words about (something) having become beautiful.
「アレ」is 「あれ」. The word, especially when in katakana, is often used to mean "that, you know", something you should understand even without explanation and/or hard to explain.
四天王最強の男は実は無能者だった的なアレじゃない？
Isn't it like the most powerful man among the 四天王 (could be a Buddhist reference or something else) is actually useless?