Alexandre Chaudret

Vindictive Lich

When this creature dies, choose one or more. Each mode must target a different player.
• Target opponent sacrifices a creature of their choice.
• Target opponent discards two cards.
• Target opponent loses 5 life.

Math is for Blockers (Plane)

Whenever a nontoken creature attacks, exile it. Return it to the battlefield under its owner's control tapped and attacking at the beginning of that player's next declare attackers step.
Whenever chaos ensues, goad target creature. (Until your next turn, It attacks each combat if able and attacks a player other than you if able.)

"20080500212151504013151514018 091905190200805002121515040131 5151400718152319. Break. Message repeats. 20080500212151504 . . ."
—Numbers station transmission

Magus of the Moon

Funeral Room // Awakening Hall

Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.
(You may cast either half. That door unlocks on the battlefield. As a sorcery, you may pay the mana cost of a locked door to unlock it.)

Brazen Borrower // Petty Theft

Flash
Flying
This creature can block only creatures with flying.

Wrexial, the Risen Deep

Islandwalk, swampwalk (This creature can't be blocked as long as defending player controls an Island or a Swamp.)
Whenever Wrexial deals combat damage to a player, you may cast target instant or sorcery card from that player's graveyard without paying its mana cost. If that spell would be put into a graveyard, exile it instead.

For a crash course in addition, hunt a single thragtusk.

Thragtusk

When this creature enters, you gain 5 life.
When this creature leaves the battlefield, create a 3/3 green Beast creature token.

Even the smallest drop of its deadly venom will subtract decades from your lifespan.

Ohran Frostfang

Attacking creatures you control have deathtouch.
Whenever a creature you control deals combat damage to a player, draw a card.

Meandering Towershell

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
Whenever this creature attacks, exile it. Return it to the battlefield under your control tapped and attacking at the beginning of the declare attackers step on your next turn.