The Phantom Knights of Cloven Helm [WIRA-EN004] Rare

The Phantom Knights of Cloven Helm [WIRA-EN004] RareSet: Wing Raiders Card type: Effect Monster Rarity: Rare Attack: 1500 Defense: 500 If a "Phantom Knights" card(s) is sent to your Graveyard: This card gains 500 ATK. You can banish this card from your Graveyard; during the End Phase of this turn, add 1 "Phantom Knights" card from your Graveyard to your hand. You can only use each effect of "The Phantom Knights of Cloven Helm" once per turn.

All Slivers have "{B}: Regenerate this permanent

Set: Commander 2018 Type: Creature — Elemental Rarity: Rare Cost: {4}{R}{G} Rubblehulk's power and toughness are each equal to the number of lands you control

What I wouldn't give to tackle an equation like that

Set: Commander 2019 Type: Artifact Rarity: Rare Cost: {5} Aeon Engine enters the battlefield tapped

Set: Classic Sixth Edition Type: Creature — Human Knight Rarity: Rare Cost: {1}{W}{W} {T}

Set: Commander Anthology Type: Instant Rarity: Uncommon Cost: {B}{G} Choose one —

If it's a Goblin permanent card

but sometimes they mindlessly attempt familiar tasks

Set: Throne of Eldraine Type: Artifact Rarity: Rare Cost: {2} As Sorcerous Spyglass enters the battlefield

where X is the number of card types the discarded card has

Set: Lorwyn Type: Creature — Elemental Rarity: Common Cost: {6}{R} Trample

Set: Commander 2020 Type: Land Rarity: Uncommon {T}: Add {C}