Winter Orb

As long as this artifact is untapped, players can't untap more than one land during their untap steps.

Magnetic Mine

Whenever another artifact is put into a graveyard from the battlefield, this artifact deals 2 damage to that artifact's controller.

Old Gnawbone

Flying
Whenever a creature you control deals combat damage to a player, create that many Treasure tokens.

Vazi, Keen Negotiator

Haste
{T}: Target opponent creates X Treasure tokens, where X is the number of Treasure tokens you created this turn.
Whenever an opponent casts a spell or activates an ability, if mana from a Treasure was spent to cast it or activate it, put a +1/+1 counter on target creature, then draw a card.

Disciple of the Vault

Whenever an artifact is put into a graveyard from the battlefield, you may have target opponent lose 1 life.

Descent into Avernus

At the beginning of your upkeep, put two descent counters on this enchantment. Then each player creates X Treasure tokens and this enchantment deals X damage to each player, where X is the number of descent counters on this enchantment.