Here is a couple of thoughts.
A card has a starting cost and for each turn it remains in hand it can cost more or less depending on the rest of the mechanic.
A card is played on turn X and a trigger happens then and again every Xth turn afterwards.
Another fun option would be "Layaway Cost" mechanics.
I.e. you get to play a chosen permanent or creature card on "Layaway"... Each turn some fixed percentage of required quanta gets funneled to it (immediately after quanta generation maybe?). The percent funneled is basically its total cost divided by "X" (the number of turns of layaway). Once its cost is paid off, it comes into play at the start of its owner's following turn.
To make it really useful, the creature could be allowed to come into play "readied" (i.e. with its active skill usable on that turn).
It could provide a fun counter to quanta denial and give
a way to extend the mark-limited portion of the SoR to other elements.
