They cannot be used as Xyz Material for an Xyz Summon, except for the Xyz Summon of a Beast, Beast-Warrior, or Winged Beast-Type monster
You can also use it politically to save an opponent from attacks, if the mood strikes you
Except Lurrus of the Dream-Den, which is just going to get to hop into a whole bunch of sideboards at very little cost and return a bunch of incredible permanents to its controllers battlefields
The Demon is an on-curve 5-cost, 5/4 flyer that turns discards or cycles into -1/-1 counters onto every opposing dork, so that'll blow through your opponent's stuff very quickly
It will Special Summon itself from your hand, and adjusts the level of any Tuner (even itself) by +/- 1, giving you maximum flexibility for your next monster to Synchro Summon
So Magic aside, all of the above mentioned games, as well as many more, use tokens to track damage, status conditions and even victory points