Polymorph

Destroy target creature. It can't be regenerated. Its controller reveals cards from the top of their library until they reveal a creature card. The player puts that card onto the battlefield, then shuffles all other cards revealed this way into their library.

Power Sink

Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.

Prodigal Sorcerer

{T}: This creature deals 1 damage to any target.

Prosperity

Circle of Protection: Blue

{1}: The next time a blue source of your choice would deal damage to you this turn, prevent that damage.

Psychic Transfer

If the difference between your life total and target player's life total is 5 or less, exchange life totals with that player.

Psychic Venom

Enchant land
Whenever enchanted land becomes tapped, this Aura deals 2 damage to that land's controller.

Recall

Discard X cards, then return a card from your graveyard to your hand for each card discarded this way. Exile Recall.

Relearn

Return target instant or sorcery card from your graveyard to your hand.

Remove Soul

Sage Owl

Flying
When this creature enters, look at the top four cards of your library, then put them back in any order.

Sea Monster

This creature can't attack unless defending player controls an Island.

Segovian Leviathan

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Sibilant Spirit

Flying
Whenever this creature attacks, defending player may draw a card.

Soldevi Sage

{T}, Sacrifice two lands: Draw three cards, then discard one of them.

Classic Sixth Edition