As some of you may or may not know, i once posted Time Leap on the forums here. I since then deleted that old post and reworked them, due to the Mechanic "Time Banish" included in them not having a place in an actual card game, therefore i reduced it to a Fanfic element at most. Now, without further ado, i shall explain Time Leap to thee. Time Leap monsters are contained within the Extra Deck, and like Xyzs or Evolutes (courtesy of Chadook), they do not feature Levels, instead they feature Futures. The way to summon them is quite easy - Fulfill a certain condition listed on the card (always on the left of the first sentence) and banish a monster that is 1 level lower than the Future of the monster your summoning, which is listed on the card (Always on the right of the first sentence). You can only Time Leap Summon once per turn, tho. Here's a quick image to show you how a Time Leap looks.
Do note, however, that certain effects on cards can have it not banish the monster they use as material, have it not be restricted to 1 Level below it, etc., etc.
Some more Examples of Time Leap monsters:
