A devestating combo is for the OL picking the Giants, use Sweep the attack action on any round and spending overlord cards to buff that attack. That means that the attack hits all heroes within "Reach" spaces and in line of sight, as well as getting the surges and extra damage etc from any card spent.
Is this intentional? Can you spend OL cards on monster abilites (Read: Not attacks) to gain more power? In that case, does the Giants "Sweep" count as an action or attack, and in which case can it be buffed by cards??