Isu the Abominable

You may look at the top card of your library any time.
You may play snow lands and cast snow spells from the top of your library.
Whenever another snow permanent you control enters, you may pay {G}, {W}, or {U}. If you do, put a +1/+1 counter on Isu.

Maralen, Fae Ascendant

Flying
Whenever Maralen or another Elf or Faerie you control enters, exile the top two cards of target opponent's library.
Once each turn, you may cast a spell with mana value less than or equal to the number of Elves and Faeries you control from among cards exiled with Maralen this turn without paying its mana cost.

Locke, Treasure Hunter

Locke can't be blocked by creatures with greater power.
Mug — Whenever Locke attacks, each player mills a card. If a land card was milled this way, create a Treasure token. Until end of turn, you may cast a spell from among those cards.

Doran, Besieged by Time

Each creature spell you cast with toughness greater than its power costs {1} less to cast.
Whenever a creature you control attacks or blocks, it gets +X/+X until end of turn, where X is the difference between its power and toughness.

Felothar the Steadfast

Each creature you control assigns combat damage equal to its toughness rather than its power.
Creatures you control can attack as though they didn't have defender.
{3}, {T}, Sacrifice another creature: Draw cards equal to the sacrificed creature's toughness, then discard cards equal to its power.

Kirol, Attentive First-Year

Tap two untapped creatures you control: Copy target triggered ability you control. You may choose new targets for the copy. Activate only once each turn.

Saruman of Many Colors

Ward—Discard an enchantment, instant, or sorcery card.
Whenever you cast your second spell each turn, each opponent mills two cards. When one or more cards are milled this way, exile target enchantment, instant, or sorcery card with equal or lesser mana value than that spell from an opponent's graveyard. Copy the exiled card. You may cast the copy without paying its mana cost.

Inspirit, Flagship Vessel

Station (Tap another creature you control: Put charge counters equal to its power on this Spacecraft. Station only as a sorcery. It's an artifact creature at 8+.)
1+ | At the beginning of combat on your turn, put your choice of a +1/+1 counter or two charge counters on up to one other target artifact.
8+ | Flying
Other artifacts you control have hexproof and indestructible.