Trial of Strength

When Trial of Strength enters, create a 4/2 green Beast creature token.
When a Cartouche you control enters, return Trial of Strength to its owner's hand.

Aluren

Any player may cast creature spells with mana value 3 or less without paying their mana costs and as though they had flash.

Trial of Knowledge

When Trial of Knowledge enters, draw three cards, then discard a card.
When a Cartouche you control enters, return Trial of Knowledge to its owner's hand.

Yarok, the Desecrated

Deathtouch, lifelink
If a permanent entering causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.

Enigmatic Incarnation

At the beginning of your end step, you may sacrifice another enchantment. If you do, search your library for a creature card with mana value equal to 1 plus the sacrificed enchantment's mana value, put that card onto the battlefield, then shuffle.

Keruga, the Macrosage

Companion — Your starting deck contains only cards with mana value 3 or greater and land cards. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.)
When Keruga, the Macrosage enters, draw a card for each other permanent you control with mana value 3 or greater.