msem-instigator

Vigilance
When Tortle Guard enters the battlefield, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may mill that card.)

Trample
{4}{R}{R}: Tortle Tinkerer explores. This ability costs {1} less to activate for each artifact you control. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may mill that card.)

{G}, {T}: Add one mana of any color. When a creature enters the battlefield this turn, if that mana was spent to cast it, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may mill that card.)

Tortle Traveler enters the battlefield tapped.
When Tortle Traveler enters the battlefield, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may mill that card.)

Whenever Tortle Veteran or another Turtle enters the battlefield under your control, that creature explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may mill that card.)

Haste
Whenever Tortle Waymaker becomes blocked, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may mill that card.)

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever a marked creature dies, target player discards a card.

Deathtouch
Heretic (Whenever you cast a spell that doesn't share a color with this creature, it gets +1/+1 until end of turn.)

Deathtouch

Vision (Whenever this or another creature enters the battlefield under your control, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Tracker of Wild Places envisions a creature card, you may untap a permanent you control.

Target creature you control fights target creature you don't control, then fights it again.

Frenzy 1 (Whenever this creature attacks and isn't blocked, it gets +1/+0 until end of turn.)
Whenever Trading Traitor deals combat damage to a player, you lose life equal to the number of unblocked attacking creatures you control and draw that many cards.

Haste
Sacrifice a land: Trail Blazer explores. You may put a basic land card from your hand onto the battlefield tapped. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then you may mill that card.)

Whenever a basic land enters the battlefield under your control, add one mana of any color.

Whenever a nonland permanent enters the battlefield under an opponent's control this turn, gain control of that permanent until the end of your next turn. It gains haste until end of turn.

At the beginning of your end step, choose any number of permanents and/or players, then give each another counter of each kind it already has.
[+1]: Scry 1. Add {U} or {R}.
[–X]: Exile the top X cards of your library. Until end of turn, you may play a card exiled with Trainee Karina Oblay.

Vanguard — Whenever a creature you control attacks alone, draw a card.

Equipped creature gets +2/+2 and has hexproof and vigilance.
Equip {2}

Whenever a creature you control attacks and isn't blocked, it explores. (Reveal the top card of your library. Put it into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then you may mill that card.)

Whenever a creature attacks you or a planeswalker you control, that creature doesn't untap during its controller's next untap step.

{T}: Add {C}.
{3}, {T}, Sacrifice Treasure Beach: Create three Treasure tokens. (They have “{T}, Sacrifice this artifact: Add one mana of any color.”)

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
Whenever a Reflection you control becomes the target of a spell, draw a card.

Untap all other artifacts you control during each other player's untap step.
{T}: Untap another target permanent.

As Tree of Timelines enters the battlefield, you may pay 3 life. If you don't, it enters the battlefield tapped.
{T}: Add {B}, {G}, or {U}.

When Trench Breaker enters the battlefield, put target creature on top of its owner's library.