Wall of Nets

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

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.

Nemesis Mask

All creatures able to block equipped creature do so.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery. This card enters unattached and stays on the battlefield if the creature leaves.)

Trap Runner

{T}: Target unblocked attacking creature becomes blocked. Activate only during combat after blockers are declared. (This ability works on creatures that can't be blocked.)

Armored Transport

Prevent all combat damage that would be dealt to Armored Transport by creatures blocking it.

Defensive Formation

Rather than the attacking player, you assign the combat damage of each creature attacking you. You can divide that creature's combat damage as you choose among any of the creatures blocking it.

Reconnaissance

{0}: Remove target attacking creature you control from combat and untap it. (If you activate during end of combat, the creature will untap after it deals combat damage.)

Serene Master

Whenever Serene Master blocks, exchange its power and the power of target creature it's blocking until end of combat.

Brave the Sands

Creatures you control have vigilance.
Each creature you control can block an additional creature each combat.

Brigid, Hero of Kinsbaile

First strike
{T}: Brigid, Hero of Kinsbaile deals 2 damage to each attacking or blocking creature target player controls.

Magnetic Web

If a creature with a magnet counter on it attacks, all creatures with magnet counters on them attack if able.
Whenever a creature with a magnet counter on it attacks, all creatures with magnet counters on them block that creature this turn if able.
{1}, {T}: Put a magnet counter on target creature.

Steadfast Armasaur

Vigilance
{1}{W}, {T}: Steadfast Armasaur deals damage equal to its toughness to target creature blocking or blocked by it.

Barrow-Blade

Equipped creature gets +1/+1.
Whenever equipped creature blocks or becomes blocked by a creature, that creature loses all abilities until end of turn.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Benalish Missionary

{1}{W}, {T}: Prevent all combat damage that would be dealt by target blocked creature this turn.

Arc Spitter

Equipped creature has "{1}: This creature deals 1 damage to target creature that's blocking it."
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Abu Ja'far

When Abu Ja'far dies, destroy all creatures blocking or blocked by it. They can't be regenerated.