Harsh Mentor

Whenever an opponent activates an ability of an artifact, creature, or land on the battlefield, if it isn't a mana ability, Harsh Mentor deals 2 damage to that player.

Spellshock

Whenever a player casts a spell, Spellshock deals 2 damage to that player.

Manabarbs

Whenever a player taps a land for mana, Manabarbs deals 1 damage to that player.

Zo-Zu the Punisher

Whenever a land enters, Zo-Zu the Punisher deals 2 damage to that land's controller.

Impatience

At the beginning of each player's end step, if that player didn't cast a spell this turn, Impatience deals 2 damage to that player.

Ankh of Mishra

Whenever a land enters, Ankh of Mishra deals 2 damage to that land's controller.

Tectonic Instability

Whenever a land enters, tap all lands its controller controls.

Scrambleverse

For each nonland permanent, choose a player at random. Then each player gains control of each permanent for which they were chosen. Untap those permanents.