Zoostuck 3

tell him that they're spies

He already thinks they're spies, judging by the way he's yelling at them for spying on him in their newfangled car gizmo. Apparently this is his punishment for them.

But you can't just leave this problem up to Roosevelt. He has no idea what they're capable of if left unchecked, and worse, if he actually decides to prosecute them, the resulting records might serve as warnings to them in the future. No, it's better to take care of loose time travel threads right here and now before there can be any sort of official records of their existence.

cripple his spinjitsu by taking advantage of his pride

Like that's easy. His pride is clearly what makes his spinjitsu so strong. Oh, sure, you might be able to pull off a minor manipulation or two, but he'd just spinjitsu his way out of whatever problem you pointed him towards and come out of it with even more pride, and consequently even more spinjitsu power.

You could, hypothetically, point him at these interlopers and get him to destroy them. But in the long term, an even stronger Teddy Roosevelt can mean nothing but trouble for your plans.

go get his fifth cousin frankie to rouse up dmx's ruff riders

Fortunately, an idea comes to you. The one thing powerful enough to stand up to a Roosevelt: another Roosevelt. In a family scuffle, his pride will be neutralized, for his relative will be just as proud.

But it's not going to be that simple. You're going to have to provoke an argument over something. How are you going to do that?