There are no legendaries’ except L’kian.
Most of the cost is for the three grail masters (epics).
Card draw: sphere of darkness and L’kian. Replace L’kian with sojourners if you need to.
The strategy is to summon gor’s and jaxi first, then play your typical swarm abyss style.
any surviving gor’s and jaxi’s by turn mana 7 should be a good place to summon grail master
next turn, use ur bbs to summon more wraithlings to proc off grail master
then let the grail master rng cancer begin