Now, as the title explains, they're a bunch of tblinks like such example, but what I ask is how they get customized ones. Can anyone explain?

The on.toribash.com links you're referring to are referral links people would sent to others to advertise Toribash, and in return that user would receive 30 toricredits per person that clicked it. This way of earning tc no longer works, and you cannot create your own on.toribash.com link either, but people still have them in their signatures from when they used to work.

Twilight Moderated Message:

This should answer your question NinjaKid. ~Closed.