Ixhel, Scion of Atraxa

Flying, vigilance, toxic 2
Corrupted — At the beginning of your end step, each opponent who has three or more poison counters exiles the top card of their library face down. You may look at and play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast those spells.

Etali, Primal Sickness

Trample, indestructible
Whenever Etali, Primal Sickness deals combat damage to a player, they get that many poison counters. (A player with ten or more poison counters loses the game.)

Etali, Primal Conqueror

Trample
When Etali, Primal Conqueror enters the battlefield, each player exiles cards from the top of their library until they exile a nonland card. You may cast any number of spells from among the nonland cards exiled this way without paying their mana costs.
{9}{G/P}: Transform Etali. Activate only as a sorcery.

Etali, Primal Conqueror // Etali, Primal Sickness

Urabrask the Hidden

Creatures you control have haste.
Creatures your opponents control enter the battlefield tapped.

Attentive Skywarden

Flying
Whenever Attentive Skywarden deals combat damage to a player or battle, transform up to one target Incubator token you control.

Omnath, Locus of All

If you would lose unspent mana, that mana becomes black instead.
At the beginning of your precombat main phase, look at the top card of your library. You may reveal that card if it has three or more colored mana symbols in its mana cost. If you do, add three mana in any combination of its colors and put it into your hand. If you don't reveal it, put it into your hand.

Tiller of Flesh

Whenever you cast a spell that targets one or more permanents, incubate 2. (Create an Incubator token with two +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)

Jin-Gitaxias, Progress Tyrant

Whenever you cast an artifact, instant, or sorcery spell, copy that spell. You may choose new targets for the copy. This ability triggers only once each turn. (A copy of a permanent spell becomes a token.)
Whenever an opponent casts an artifact, instant, or sorcery spell, counter that spell. This ability triggers only once each turn.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Omnath, Locus of Mana

You don't lose unspent green mana as steps and phases end.
Omnath, Locus of Mana gets +1/+1 for each unspent green mana you have.

Alabaster Host Sanctifier

Furnace-Blessed Conqueror

Whenever Furnace-Blessed Conqueror attacks, create a tapped and attacking token that's a copy of it. Put a +1/+1 counter on that token for each +1/+1 counter on Furnace-Blessed Conqueror. Sacrifice that token at the beginning of the next end step.

Sun-Blessed Guardian

{5}{R/P}: Transform Sun-Blessed Guardian. Activate only as a sorcery. ({R/P} can be paid with either {R} or 2 life.)

Sun-Blessed Guardian // Furnace-Blessed Conqueror

Norn's Inquisitor

When Norn's Inquisitor enters the battlefield, incubate 2. (Create an Incubator token with two +1/+1 counters on it and "{2}: Transform this artifact." It transforms into a 0/0 Phyrexian artifact creature.)
Whenever a permanent you control transforms into a Phyrexian, put a +1/+1 counter on it.