mtg 13 card The Number Thirteen WILL KILL YOU! if you have exactly thirteen cards in your hand 13 more Magic: The Gathering

A return to Magic's past, Core Sets are back!

Note that there are no brakes here like once per turn or one class of spell like non-creatures

Most instances of either gating condition are on activated abilities (most of which don't cost mana and therefore need a limiting condition), neatly solving the issue I'm about to mention, but consider this example: We're playing Innistrad Crimson Vow draft

Loxi: Rodolf is cool, but he's a bit expensive and combines two archetypes that might be a bit hard to slap together

This means, with enough methods to get those double-triggers in your deck, your creatures will grow into terrifying threats very quickly