When Ashara attacks with exactly one other unit, she gets +4 Attack and Quickdraw this turn. At the end of the turn, she kills the unit.
Deadly - Units and spells with Deadly kill any unit they damage, regardless of health. For example, a 1/1 with Deadly can kill a 5/5 attacker.
Quickdraw - Units with Quickdraw kill blockers before they can deal damage back. Note that Quickdraw only works while attacking, not while blocking.