msem-instigator

Flash
When Caronas, Eon Wanderer enters, you gain 2 life and draw two cards if Caronas, Eon Wanderer isn't on the battlefield.
{2}{W}{U}, Discard two cards: Aetherize Caronas. (To aetherize, create a token that's a copy of it, then exile that token.)

Flying, prowess
When Chronosphere Sovereign enters, nonbasic permanents target opponent controls don't untap during their controller's next untap step.
When Chronosphere Sovereign dies, it deals 3 damage to each tapped creature you don't control. Destroy each tapped artifact you don't control.

Search your library for a basic land card and put that card onto the battlefield, then shuffle.
{5}{G}{W}, Exile Claim for Civilization from your graveyard: Create a 6/6 colorless Golem artifact creature token. Activate only as a sorcery.

Flying, lifelink
When Cloudshaper Pilgrim enters, return target creature or enchantment card with mana value 3 or less from your graveyard to your hand.

({T}: Add {R} or {W}.)
Cloudsteel Summit enters tapped.
{1}, {T}: Add {R}{R} or {W}{W}.

Enchant land
When Contested Discovery enters and at the beginning of your upkeep, untap enchanted land. You gain control of that land until end of turn.

Crater Burst deals 3 damage to any target. Add {W}{U}{B}{R}{G}. Until end of turn, you don't lose this mana as steps and phases end.

Flying
Wanderlust — When Crest Skimmer enters, if you control four or more differently named lands, draw a card.

Hexproof
Crossworld Wanderer gets +1/+1 for each differently named land you control.

When Cryptic Sentinel enters, attach any number of target Auras you control to Cryptic Sentinel.
{G}{W}, Sacrifice an Aura: Tap Cryptic Sentinel. It gains indestructible until end of turn.

({T}: Add {W} or {B}.)
Cursed Wastes enters tapped.
{1}, {T}: Add {W}{W} or {B}{B}.

When Customs Lookout enters, each player draws a card, then discards a card.
Whenever an opponent casts a spell with the same name as a card they own in exile or in their graveyard, you may scry 2.

When Deliver from Dilapidation enters, you may sacrifice any number of enchantments. Whenever you sacrifice an enchantment this way, destroy target creature.
At the beginning of your upkeep, return target enchantment card with mana value 5 or less from your graveyard to the battlefield.

{T}: Each of two other target permanents you control that share a card type become a copy of the other until end of turn.

Counter target spell or activated ability. If an activated ability of an artifact was countered this way, put that permanent on the bottom of its owner's library.

Destroy target creature or planeswalker. Draw a card.

Flying, menace
When Dreadfire Tyrant enters, target opponent reveals their hand. You may put a creature or planeswalker card from it onto the battlefield under your control. That permanent gains haste and “At the beginning of your end step, sacrifice a permanent you control.”
When Dreadfire Tyrant dies, each opponent loses 5 life. You gain life equal to the life lost this way.

Dustchoked Outpost enters tapped.
When Dustchoked Outpost enters, create a 1/1 Scout creature token that's all colors. It gains haste until end of turn. Sacrifice it at the beginning of the next end step.
{T}: Add {R}.

When Embrace the Veil enters, you may exile target nonland permanent you don't control until Embrace the Veil leaves the battlefield.
Whenever you cast a spell with mana value 5 or greater, you may put a card exiled with Embrace the Veil into its owner's graveyard and return Embrace the Veil to its owner's hand.

Flying
Crew 4 (Tap any number of creatures you control with total power 4 or greater: This Vehicle becomes an artifact creature until end of turn.)
Tap two untapped other artifacts you control: Encampment Blimp becomes an artifact creature until end of turn. Scry 1.

When Endless Trove enters, if it's not a token, each opponent may create a token that's a copy of it.
{T}: Add one mana of any color.

Double strike
Experience (Whenever this creature attacks, if it has fewer than three +1/+1 counters on it, put a +1/+1 counter on it.)

Return target card from your graveyard to your hand. Distribute X +1/+1 counters among any number of creatures you control, where X is that card's mana value. Exile Entropic Harvest.

Flying, haste
Whenever Epoch Warden attacks, you may aetherize another target attacking creature you control. (To aetherize, create a token that's a copy of it, then exile that token.)

{T}: Add {C}. Put a fusion counter on Eternal Reactor.
{2}, {T}: Add {C} for each fusion counter on Eternal Reactor.