Delay might be decent while we’re employing a tempo plan, but it doesn’t do much when we want to grind opponents out. Leak does both. It’s true that Leak is weaker in the late-game, but once we’re in the late-game, our chances of tempo-ing out opponents drops significantly. This makes Leak better than Delay in pretty much any stage of the game.

Have you ever thougt of using delay instead of manaleak?
In theory it seems like it does excactly what ypu want