Euryd, the Drifting Song

Endurance - Units with Endurance ready at the start of each players turn, so they can attack and still be ready to block during the enemy turn. Additionally, they are completely immune to enemy stun and exhaust effects.

Entomb - The ability of a unit with Entomb will activate when it dies. This combines well with effects that sacrifice units as a cost.

Flying - Flying units can only be blocked by other flying units, but can block ground units normally. They can also be directly attacked by Killer units and Relic Weapons.

Quickdraw - Units with Quickdraw kill blockers before they can deal damage back. Note that Quickdraw only works while attacking, not while blocking.