Thought Scour

Target player mills two cards.
Draw a card.

Snow-Covered Island

Target player mills four cards. (Then exile this card. You may cast the creature later from exile.)

All creatures get -2/-2 until end of turn. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Draw three cards.
Islandcycling {1} ({1}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Whenever another snow permanent you control enters, you may have target player mill two cards.

Target player mills five cards.
Cycling {U} ({U}, Discard this card: Draw a card.)

({T}: Add {U} or {B}.)
Ice Tunnel enters tapped.

Counter target spell. Its controller mills three cards.

Target player mills two cards. Draw two cards.

Lifelink
When Desperate Bloodseeker enters, target player mills two cards. (They put the top two cards of their library into their graveyard.)