mtg commander masters booster box Collector pack with a chance to find a Borderless Foil Mythic Rare 1–4 Borderless cards per pack Commander Masters CMM Set Booster

They are associated with a specific color of mana, and you "tap" (turn sideways) them to add a mana of that color to your mana pool

Thats not too bad of an effect, but you need to have something good to bring back, make sure youre not exiling so many cards as to turn off other delirium effects, and then make sure youre not exiling something youd want to bring back later

They aren't

Full-art like Briar lead with 16% yearly gains, while ex like Galvantula ex hold 9% monthly, per TCGPlayer

Flexible enough to take out enemy creatures or delivery the final points of 'reach' to spell doom for foes at low life totals

however, I will let you all read the overload on Break the Ice instead