Maddening Cacophony

Kicker {3}{U}
Each opponent mills eight cards. If this spell was kicked, instead each opponent mills half their library, rounded up.

Sol Ring

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)

Traumatize

Target player mills half their library, rounded down.

The Mindskinner

The Mindskinner can't be blocked.
If a source you control would deal damage to an opponent, prevent that damage and each opponent mills that many cards.

Tempest Djinn

Flying
Tempest Djinn gets +1/+0 for each basic Island you control.

Fleet Swallower

Whenever Fleet Swallower attacks, target player mills half their library, rounded up.