Test of Endurance

At the beginning of your upkeep, if you have 50 or more life, you win the game.

Tolsimir, Friend to Wolves

When Tolsimir, Friend to Wolves enters, create Voja, Friend to Elves, a legendary 3/3 green and white Wolf creature token.
Whenever a Wolf you control enters, you gain 3 life and that creature fights up to one target creature you don't control.

Seedtime

Cast this spell only during your turn.
Take an extra turn after this one if an opponent cast a blue spell this turn.

Aetherflux Reservoir

Whenever you cast a spell, you gain 1 life for each spell you've cast this turn.
Pay 50 life: Aetherflux Reservoir deals 50 damage to any target.

Rebuff the Wicked

Counter target spell that targets a permanent you control.

Lapse of Certainty

Counter target spell. If that spell is countered this way, put it on top of its owner's library instead of into that player's graveyard.

Vigilant Martyr

Sacrifice Vigilant Martyr: Regenerate target creature.
{W}{W}, {T}, Sacrifice Vigilant Martyr: Counter target spell that targets an enchantment.