Masako the Humorless

Flash
Tapped creatures you control can block as though they were untapped.

Boldwyr Intimidator

Cowards can't block Warriors.
{R}: Target creature becomes a Coward until end of turn.
{2}{R}: Target creature becomes a Warrior until end of turn.

Patron of the Kitsune

Fox offering (You may cast this spell any time you could cast an instant by sacrificing a Fox and paying the difference in mana costs between this and the sacrificed Fox. Mana cost includes color.)
Whenever a creature attacks, you may gain 1 life.

Darien, King of Kjeldor

Whenever you're dealt damage, you may create that many 1/1 white Soldier creature tokens.

Bedlam

Convulsing Licid

{R}, {T}: Convulsing Licid loses this ability and becomes an Aura enchantment with enchant creature. Attach it to target creature. You may pay {R} to end this effect.
Enchanted creature can't block.

Fumiko the Lowblood

Fumiko the Lowblood has bushido X, where X is the number of attacking creatures. (Whenever this creature blocks or becomes blocked, it gets +X/+X until end of turn.)
Creatures your opponents control attack each combat if able.

Lieutenant Kirtar

Flying
{1}{W}, Sacrifice Lieutenant Kirtar: Exile target attacking creature.

Michiko Konda, Truth Seeker

Whenever a source an opponent controls deals damage to you, that player sacrifices a permanent of their choice.

Agrus Kos, Wojek Veteran

Whenever Agrus Kos, Wojek Veteran attacks, attacking red creatures get +2/+0 and attacking white creatures get +0/+2 until end of turn.

Grand Melee

All creatures attack each combat if able.
All creatures block each combat if able.

Urabrask the Hidden

Creatures you control have haste.
Creatures your opponents control enter tapped.

Demoralize

All creatures gain menace until end of turn. (They can't be blocked except by two or more creatures.)
Threshold — If seven or more cards are in your graveyard, creatures can't block this turn.