Mayhem Patrol

Menace (This creature can't be blocked except by two or more creatures.)
Whenever Mayhem Patrol attacks, target creature gets +1/+0 until end of turn.
Blitz {1}{R} (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)

Eater of Virtue

Whenever equipped creature dies, exile it.
Equipped creature gets +2/+0.
As long as a card exiled with Eater of Virtue has flying, equipped creature has flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, protection, reach, trample, and vigilance.
Equip {1}

Blood Petal Celebrant

Blood Petal Celebrant has first strike as long as it's attacking. (It deals combat damage before creatures without first strike.)
When Blood Petal Celebrant dies, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Flame-Blessed Bolt

Flame-Blessed Bolt deals 2 damage to target creature or planeswalker. If that creature or planeswalker would die this turn, exile it instead.

Falkenrath Perforator

Whenever Falkenrath Perforator attacks, it deals 1 damage to defending player.

Goldhound

First strike
Menace (This creature can't be blocked except by two or more creatures.)
{T}, Sacrifice Goldhound: Add one mana of any color.

Deadly Dancer

Trample
When this creature transforms into Deadly Dancer, add {R}{R}. Until end of turn, you don't lose this mana as steps and phases end.
{R}{R}: Deadly Dancer and another target creature each get +1/+0 until end of turn.

Alluring Suitor

When you attack with exactly two creatures, transform Alluring Suitor.

Alluring Suitor // Deadly Dancer

Radha's Firebrand

Whenever Radha's Firebrand attacks, target creature defending player controls with power less than Radha's Firebrand's power can't block this turn.
Domain — {5}{R}: Radha's Firebrand gets +2/+2 until end of turn. This ability costs {1} less to activate for each basic land type among lands you control. Activate only once each turn.

Sticky Fingers

Enchant creature
Enchanted creature has menace and "Whenever this creature deals combat damage to a player, create a Treasure token." (It can't be blocked except by two or more creatures. The token is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
When enchanted creature dies, draw a card.

High-Speed Hoverbike

Flash
Flying
When High-Speed Hoverbike enters, tap up to one target creature.
Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Reckless Impulse

Exile the top two cards of your library. Until the end of your next turn, you may play those cards.

Strangle

Strangle deals 3 damage to target creature or planeswalker.

Hammerhand

Enchant creature
When Hammerhand enters, target creature can't block this turn.
Enchanted creature gets +1/+1 and has haste.

Lightning Strike

Lightning Strike deals 3 damage to any target.

Kessig Wolfrider

Menace
{2}{R}, {T}, Exile three cards from your graveyard: Create a 3/2 red Wolf creature token.

Belligerent Guest

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Whenever Belligerent Guest deals combat damage to a player, create a Blood token. (It's an artifact with "{1}, {T}, Discard a card, Sacrifice this artifact: Draw a card.")

Yotia Declares War

Read ahead (Choose a chapter and start with that many lore counters. Add one after your draw step. Skipped chapters don't trigger. Sacrifice after III.)
I — Create a 0/2 colorless Thopter artifact creature token with flying named Ornithopter.
II — Tap any number of untapped artifacts you control. When you do, Yotia Declares War deals that much damage to target creature or planeswalker.
III — Up to one target artifact you control becomes an artifact creature with base power and toughness 4/4 until end of turn.

Lizard Blades

Double strike
Equipped creature has double strike.
Reconfigure {2} ({2}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Yavimaya Steelcrusher

Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.)
{1}, Sacrifice Yavimaya Steelcrusher: Destroy target artifact.

Lunar Frenzy

Target creature you control gets +X/+0 and gains first strike and trample until end of turn.

Ogre-Head Helm

Equipped creature gets +2/+2.
Whenever Ogre-Head Helm or equipped creature deals combat damage to a player, you may sacrifice it. If you do, discard your hand, then draw three cards.
Reconfigure {3} ({3}: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Abrade

Choose one —
• Abrade deals 3 damage to target creature.
• Destroy target artifact.

Goro-Goro, Disciple of Ryusei

{R}: Creatures you control gain haste until end of turn.
{3}{R}{R}: Create a 5/5 red Dragon Spirit creature token with flying. Activate only if you control an attacking modified creature. (Equipment, Auras you control, and counters are modifications.)