Infiltration Lens

Whenever equipped creature becomes blocked by a creature, you may draw two cards.
Equip {1}

Jangling Automaton

Whenever this creature attacks, untap all creatures defending player controls.

Elven Warhounds

Whenever this creature becomes blocked by a creature, put that creature on top of its owner's library.

Brushwagg

Whenever this creature blocks or becomes blocked, it gets -2/+2 until end of turn.

Gorilla Berserkers

Trample; rampage 2 (Whenever this creature becomes blocked, it gets +2/+2 until end of turn for each creature blocking it beyond the first.)
This creature can't be blocked except by three or more creatures.

Aisling Leprechaun

Whenever this creature blocks or becomes blocked by a creature, that creature becomes green. (This effect lasts indefinitely.)

Tolarian Entrancer

Whenever this creature becomes blocked by a creature, gain control of that creature at end of combat.

Cathedral of Serra

White legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Likeness of the Seeker

Whenever this creature becomes blocked, untap up to three lands you control.

Azusa's Many Journeys

(As this Saga enters and after your draw step, add a lore counter.)
I — You may play an additional land this turn.
II — You gain 3 life.
III — Exile this Saga, then return it to the battlefield transformed under your control.

Azusa's Many Journeys // Likeness of the Seeker

Vortex Elemental

{U}: Put this creature and each creature blocking or blocked by it on top of their owners' libraries, then those players shuffle.
{3}{U}{U}: Target creature blocks this creature this turn if able.

Taunting Elf

All creatures able to block this creature do so.

Helm of Chatzuk

{1}, {T}: Target creature gains banding until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding a player controls are blocking or being blocked by a creature, that player divides that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Formation

Target creature gains banding until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding a player controls are blocking or being blocked by a creature, that player divides that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)
Draw a card at the beginning of the next turn's upkeep.

Ferocity

Enchant creature
Whenever enchanted creature blocks or becomes blocked, you may put a +1/+1 counter on it.

Sylvan Basilisk

Whenever this creature becomes blocked by a creature, destroy that creature.

Wall of Caltrops

Defender (This creature can't attack.)
Whenever this creature blocks a creature, if at least one other Wall creature is blocking that creature and no non-Wall creatures are blocking that creature, this creature gains banding until end of turn. (If any creatures with banding you control are blocking a creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by.)

Venom

Enchant creature
Whenever enchanted creature blocks or becomes blocked by a non-Wall creature, destroy the other creature at end of combat.

Infinite Authority

Enchant creature
Whenever enchanted creature blocks or becomes blocked by a creature with toughness 3 or less, destroy the other creature at end of combat. At the beginning of the next end step, if that creature was destroyed this way, put a +1/+1 counter on the first creature.

Seafarer's Quay

Blue legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

General Jarkeld

{T}: Choose two target blocked attacking creatures. If each of those creatures could be blocked by all creatures that the other is blocked by, each creature that's blocking exactly one of those attacking creatures stops blocking it and is blocking the other attacking creature. Activate only during the declare blockers step.

Primordial Sage

Whenever you cast a creature spell, you may draw a card.

Thicket Basilisk

Whenever this creature blocks or becomes blocked by a non-Wall creature, destroy that creature at end of combat.

Awakening

At the beginning of each upkeep, untap all creatures and lands.

Cooperation

Enchant creature
Enchanted creature has banding. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding a player controls are blocking or being blocked by a creature, that player divides that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Adventurers' Guildhouse

Green legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Godsend

Equipped creature gets +3/+3.
Whenever equipped creature blocks or becomes blocked by one or more creatures, you may exile one of those creatures.
Your opponents can't cast spells with the same name as a card exiled with Godsend.
Equip {3}

Taunting Arbormage

Kicker {3} (You may pay an additional {3} as you cast this spell.)
When this creature enters, if it was kicked, all creatures able to block target creature this turn do so.

Odric, Master Tactician

First strike (This creature deals combat damage before creatures without first strike.)
Whenever Odric and at least three other creatures attack, you choose which creatures block this combat and how those creatures block.

Kjeldoran Frostbeast

At end of combat, destroy all creatures blocking or blocked by this creature.

Beast Whisperer

Whenever you cast a creature spell, draw a card.

Engulfing Slagwurm

Whenever this creature blocks or becomes blocked by a creature, destroy that creature. You gain life equal to that creature's toughness.

Mountain Stronghold

Red legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Noble Quarry

Bestow {5}{G} (If you cast this card for its bestow cost, it's an Aura spell with enchant creature. It becomes a creature again if it's not attached to a creature.)
All creatures able to block this creature or enchanted creature do so.
Enchanted creature gets +1/+1.

Wall of Nets

Defender (This creature can't attack.)
At end of combat, exile all creatures blocked by this creature.
When this creature leaves the battlefield, return all cards exiled with it to the battlefield under their owners' control.

Nature's Blessing

{G}{W}, Discard a card: Put a +1/+1 counter on target creature or that creature gains banding, first strike, or trample. (This effect lasts indefinitely. Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding a player controls are blocking or being blocked by a creature, that player divides that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Cockatrice

Flying
Whenever this creature blocks or becomes blocked by a non-Wall creature, destroy that creature at end of combat.

Venomous Dragonfly

Flying
Whenever this creature blocks or becomes blocked by a creature, destroy that creature at end of combat.

Baton of Morale

{2}: Target creature gains banding until end of turn. (Any creatures with banding, and up to one without, can attack in a band. Bands are blocked as a group. If any creatures with banding a player controls are blocking or being blocked by a creature, that player divides that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Corrosive Ooze

Whenever this creature blocks or becomes blocked by an equipped creature, destroy all Equipment attached to that creature at end of combat.

Tangle Asp

Whenever this creature blocks or becomes blocked by a creature, destroy that creature at end of combat.

Golgari Decoy

All creatures able to block this creature do so.
Scavenge {3}{G}{G} ({3}{G}{G}, Exile this card from your graveyard: Put a number of +1/+1 counters equal to this card's power on target creature. Scavenge only as a sorcery.)

Unholy Citadel

Black legendary creatures you control have "bands with other legendary creatures." (Any legendary creatures can attack in a band as long as at least one has "bands with other legendary creatures." Bands are blocked as a group. If at least two legendary creatures you control, one of which has "bands with other legendary creatures," are blocking or being blocked by the same creature, you divide that creature's combat damage, not its controller, among any of the creatures it's being blocked by or is blocking.)

Grasping Giant

Vigilance
Whenever this creature becomes blocked by a creature, exile that creature until this creature leaves the battlefield.