Tezzeret, Emissary of the Eternities

Legendary Artifact Creature - Human Artificer

Ward: Sacrifice a colorless permanent.

Defender

Whenever a player casts a colorless spell, that you may tap ~. If you do, copy that spell. You may choose new targets for the copy.

Untap ~ at the beginning of each upkeep.

2/5

"Once, a bridge to planes; now, a bridge to non-existence."

Wild!

Kosei, Abject Adjunct

Legendary Creature - Ogre Monk Advisor

Ward: Exile an Instant or Sorcery card from your hand or graveyard.

Mentor

Whenever ~ attacks, you may distribute X +1/+1 counters among any number of creatures you control with less power or toughness than ~. If a creature would have power or toughness equal to ~ this way, you may draw a card.

"Kamigawa teaches us that our history may not decide our future, but our present certainly does."

4/5

I think that Strixhaven, following the invasion from Phyrexia, would want to incorporate more teachers from among the planes! So, maybe some "Temporary" professors that teach many of the schools from new perspectives! I think that is certainly in order for the plane, and fits thematically!

Maybe some more, or wild!

Assemble the Oathsworn

Instant

Choose an Oath. (An Oath is tied to the "Oaths" of the Gatewatch, where each one is either WUBRG, BW, UW, or GW. i.e Oath of Chandra and Oath of Teferi. Each Oath would be an outside the game tracked status tied to each player when they use an Oathsworn Card. For example:)

Search your library for a basic land that shares a color with your Oath. Put it onto the battlefield tapped. If you control a Planeswalker that shares a type with your Oath, untap it and put a Loyalty Counter on that Planeswalker.

"Though their Oath was forged, some took their mission, and expanded its focus."

Maybe that makes sense? If not, feel free to repeat or Wild. If it does, continue with cards that would use Oath's, maybe making more, or expanding their interactions with new cards!

Dauthi Bloodreaver

Creature — Dauthi Berserker

Shadow (This creature can block or be blocked only by creatures with shadow.)

Whenever Dauthi Bloodreaver deals combat damage to a player, that player discards a card at random. If they can't, exile the top two cards of their library and you may play them this turn.

: Sacrifice a creature: Dauthi Bloodreaver gets +2/+0 until end of turn.

2/1

"They do not kill for pleasure. They kill to be real."

Create a card that represents a weapon, spell, or entity that grows stronger the more it is opposed!

Djinn Judge

Creature - Djinn Gamer

Whenever a player either calls for a Magic: the Gathering Judge, or has a question about interaction or rule, you may search your library for ~, and put it onto the battlefield.

If a rule or interaction would be questioned, instead of referring to a Judge or the Gatherer, you may interpret the interaction or rule as you see fit. (The new rule cannot be inherently against or for any particular player, but your best guess as to the intended result or ruling.)

Flying

3/2

"If you think Cheatyface is bad, wait until I start interpreting layers!"

Continue, or repeat? I hope this works!