[There's a reason he's easing into the explanation.]

That's not a bad way to picture it.

Time is like a large river. It has its own path, and its own current. If you disrupt the flow, either by forcing it to flow the wrong way, trapping the current... or by damming it into a pond too small for it... it won't be pretty.

The place I came from was an abandoned timeline. Like a stagnant pond, where all the fish go to die. Time doesn't flow.

[The corner of his lip goes up. It's not as though there's anything funny, but the expression is there anyway.]

What the Witch Ish is doing, or trying to do, is like forcing water upstream or controlling a current that isn't really his to control. The water wants to go its own way. And then the stagnant pond water is added. It overflows.

Now they're mixing together.