Bloodmist Infiltrator

Whenever this creature attacks, you may sacrifice another creature. If you do, this creature can't be blocked this turn.

Prowler's Helm

Equipped creature can't be blocked except by Walls.
Equip {2}

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Armored Ascension

Enchant creature
Enchanted creature gets +1/+1 for each Plains you control and has flying.

Key to the City

{T}, Discard a card: Up to one target creature can't be blocked this turn.
Whenever this artifact becomes untapped, you may pay {2}. If you do, draw a card.

Dragon Scales

Enchant creature
Enchanted creature gets +1/+2 and has vigilance.
When a creature with mana value 6 or greater enters, you may return this card from your graveyard to the battlefield attached to that creature.

Ria Ivor, Bane of Bladehold

Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
At the beginning of combat on your turn, the next time target creature would deal combat damage to one or more players this combat, prevent that damage. If damage is prevented this way, create that many 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This token can't block."

Dragon Shadow

Enchant creature
Enchanted creature gets +1/+0 and has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When a creature with mana value 6 or greater enters, you may return this card from your graveyard to the battlefield attached to that creature.