"Oh. Yeah that's different. Why are there two different Ardas like that?—for that matter, there are other Earths, but none of them have parahumans? How's that?"

"There are seven Ardas we've found so far. All of them except Shadow and Space are the same except for a single point of divergence. There are about as many Earths, but they have a couple more points of divergence - in particular, no two Earths have the same magic system. We don't know why it works that way."

"Is this the only Earth without any magic at all? Parahuman powers don't count, right? You could replicate my stuff—although I guess just because I made it doesn't mean it's magic—Glaistig Uaine thinks she does magic..."

"Warp's Earth and Cube's are no-magic too. I dunno if parahuman powers count or not."

"Well, guess we can figure that out later—oh, I forgot to mention, when you duplicated those batteries, they might not work perfectly forever? 'Cause tinker tech tends to spontaneously fail for no reason we know of if it's not looked after by the tinker who originally made it."

"...huh. After how long?"

"Depends! But like a month is sometimes enough if the tinker literally never looks at it again for problems to appear."

"...I could make tinker-tech and tinker-tech-a-month-later and see if we can find differences."

"You can do that? How? Could you use that to simulate anything aging? Could you use that to predict stuff?"

"Can't predict things, no, but I can pull anything that existed out of any time period."

"Oh, so you mean like, something a tinker has already made in the past, not like what my batteries would be if I spent a month without doing maintenance."

"Yeah - well, we could play around with relativity, but that's not looking into the future -"

"Yeah, I was actually wondering about that, like, technically we're in the Earth's past right now, and vice-versa—and how did your magic even pick up a given time to arrive here?—but anyway, you could see if you can find anything by conjuring stuff that aged without maintenance. Might not work anyway, though, tinker tech is notoriously difficult to reverse-engineer and pretty much impossible to understand unless you're the one who made it originally."

"I have no idea how the magic handles time, except that demons sort of even things out, since we can conjure from anywhere instantaneously - you could say we have a frame of reference outside the dimension? I'm not really sure - anyway, if you name some tinker tech that ages I can see if we can get anywhere."

So he suggests this one stun gun he made like two years ago and hasn't touched in about that long.

Here it is! And here is it-when-he-made-it and here is it-a-year-ago.

They don't look different at all, modulo regular wear and tear.

Do they all work?

They seem to turn on and all but figuring out whether they work as intended would require stunning someone.

"I'm curious if local stunners work on me anyway."

"Should I try the brand-new one?"

"Sure."

He does!

Stun weapons work fine on indestructible people, though they wake up a little faster than usual.

Hero blinks and reports this.