I think it should have a repeatable ability like photosynthesis for adding counters, but whenever your opponent pays to summon a card (after 1 has already been summoned that turn) , the summon fails, they keep the card, but a counter goes away.
The reason I said "pays to summon a card" is to stop them from being able to beat it with RoL alone.
That way, it essentially is a race between your entropy production and their production of whatever the element is they are trying to multiple summon. That way, you can't guarantee that this lasts a set number of turns by making it immaterial, and both players can influence how long it lasts.