The “commander tax” increases based on how many times a commander was cast from the command zone. Casting a commander from your hand doesn’t require that additional cost, and it doesn’t increase what the cost will be the next time you cast that commander from the command zone.
23-08-2019
wotc
If your commander isn’t on the battlefield (or if you’re not playing the Commander variant), Sanctum of Eternity’s second ability does nothing.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.