Heelseeker Bow
Artifact — Equipment
Equipped creature has ": This creature deals 1 damage to target attacking or blocking creature. This damage can't be prevented."
Permanents your opponents control with hexproof or protection can be the targets of equipped creature's abilities as though they didn't have hexproof or protection.
Equip

Godless Pantheon
Land (R)
: Add one mana of any color. You lose 2 life if your devotion to that color is less than five.

Tarkir

Faithful Shield-Kin
Creature — Human Soldier
Outlast
Each creature you control with a +1/+1 counter on it has ward , where X is the number of +1/+1 counters on it.
"The dragons are long gone, but their scales remain as testament to their endurance."
2/1

Added Arcavios to the OP. This is the plane where Strixhaven is set

Student of the Untouchable
Creature — Human Monk
Prowess
Student of the Untouchable has ward , where X is its power.
She can run between sunlight and dodge the wind.
2/1

Desert Survivalist
Creature — Orc Scout
Outlast
Whenever a creature you control with a +1/+1 counter dies, draw a card and lose 1 life.
"We are not Sultai, grasping at eternal luxury. We are Abzan. I may not survive, but my family and my clan shall."
1/1

Dragonfire Channeler

Creature -- Human Shaman (U)
, , Discard a Dragon card: Dragonfire Channeler deals 3 damage to any target.
“Destruction incarnate, hear my call!”
3/2

Kin-Garden Cultivator
Creature — Human Druid
Outlast
Whenever Kin-Garden Cultivator outlasts, you may activate outlast abilities by paying rather than paying outlast costs until end of turn.
"A fruit on one branch means the whole tree is fruiting."
2/2

Ojutai's Teachings

Enchantment (R)
When Ojutai's Teachings enters the battlefield, exile the top five cards of your library.
You may cast nonland cards exiled by Ojutai's Teachings. Spells cast this way cost more to cast for each other nonland card exiled by Ojutai's Teachings.
"The first step is always the hardest." —Ojutai, Soul of Winter

Dragonstorm Elemental
Creature — Elemental
Flying
Whenever Dragonstorm Elemental attacks, you may search your library for a Dragon creature card, reveal it, then manifest it. If you do, shuffle.
Ugin's power without his curiosity or temperance.
5/1

Dragonlord's Seat
Land (R)
: Add .
: Add two mana in any combination of colors. Spend this mana only to cast an Elder Dragon spell or to activate an ability of an Elder Dragon.

Kaladesh

Aetherflow Regulator
Creature — Dwarf Advisor
At the beginning of each end step, if an opponent got two or more this turn, you draw a card and get .
"You think if we just let the aether flow freely, it will all be fine? Fine. Let's test that theory."
0/3

Aether Leak

Instant (U)
Counter target spell unless its controller pays . Then each player gains .

Incarnation of Ash
Creature — Aetherborn Rogue
Flash
At the beginning of your end step, if you spent at least three this turn, return Incarnation of Ash from your graveyard to your hand.
As the aetherborn dissolved back into the atmosphere, they realized death for their kind was not the end.
2/1

Aetherstorm Elemental

Creature -- Elemental (R)
Haste
When Aetherstorm Elemental enters the battlefield, you lose all your . Put that many +1/+1 counters on Aetherstorm Elemental.
Whenever Aetherstorm Elemental deals combat damage to a player, you gain that much .
2/2

Spiralpetal Masterpiece
Artifact Creature — Hydra
Fabricate X
Spiralpetal Masterpiece has ward , where X is the number of creatures you control.
The first designer was nature and everyone else have been imitators.
0/0

Unveil the Masterpiece
Sorcery
As an additional cost to cast this spell, pay X .
Choose two artifact cards you own from outside the game with total mana value X or less. Reveal them. Create Aetherwork Masterpiece, a legendary artifact token with all of those artifact cards' abilities.

Crackling Saber

Artifact -- Equipment (U)
When Crackling Saber enters the battlefield, gain .
Equipped creature gets +1/+0 for each you have and has first strike.
Equip

Renegade Gatherhall
Land
Renegade Gatherhall enters the battlefield tapped.
When Renegade Gatherhall enters the battlefield, you may discard a card. If you do, draw a card.
: Add

Next is Amonkhet.

All-Crop Initiate

Creature -- Human Warrior (C)
Survivor (At the beginning of combat on your turn, put a +1/+1 counter on this creature if it attacked this combat.)
"The Hekma is a more dangerous trial than any we faced back in Naktamun."
2/1