No You Don't Understand!

I don't know moonrunes at all, but I was trying to turn the phrase "You are already dead / Omae wa mō shinde iru (お前はもう死んでいる)" into "You already understand" because that face is pretty Hokuto no Ken-looking to me and I wanted to be clever… I've come up with "Omae sudeni rikai shite iru (お前すでに 理解 して いる)" after trying to force it to use some of the words from the original phrase to replace the ones Google translate gave me. With Google translate I could probably come up with hundreds of different ways to write it and probably none of them would be the right one… someone pls halp.

First panel is from the NSFW hentai manga "Sweet and Sour" by Yakiniku King.