Oath of Teferi

+1: Add RRR. Spend this mana only to cast instant or sorcery spells. +1: Discard up to three cards, then draw that many cards. −8: You get an emblem with "You may cast instant and sorcery spells from your graveyard. If a spell cast this way would be put into your graveyard, exile it instead."

This land enters tapped unless you control an Island or a Mountain. T: Add U or R.

This land enters tapped unless you control a Plains or a Swamp. T: Add W or B.

First strike When this creature enters, it deals 1 damage to each opponent and each creature and planeswalker they control.

T: Add three mana of any one color.

Trample Whenever you cast a spell, if that spell was kicked, put a +1/+1 counter on Hallar, then Hallar deals damage equal to the number of +1/+1 counters on it to each opponent.

Flying Whenever you cast a historic spell, return target creature card with mana value 3 or less from your graveyard to the battlefield. (Artifacts, legendaries, and Sagas are historic.)