Wrathscale Naga could be used by couple ways.
Be well with Fel’dorei Warband
And Coordinated Strike at the best option ur table is full of minions by last turn when play this and send one by one ur minions to death with nicely 3dmg for each, in fact when at least 4minions die its 12 dmg by Wrath and died minions own atack so at least 16+ dmg. And we just spend 3mana for Wrath and kill small minions survived last turn .Next card u play about situation. Against big minions summon rushers many of u could and continue using Wrath.
But if enemy table s empty soon , use Keen and get attack for each died 1hp minion, also dont lost wrath before our minions die xD
Optional could be played against small minions or when Kurtrus, Demon-Render is played (probably not against cc spells xD ) possible summon full table illidaries and ,when we are absolutelly sure there is no way to smash them , wait to next turn by possibillity attack all of them to enemy hero for use passive for each and use Keen Reflex and get 1+ attack for each illidari too ????
Thats two cards i thinked about few time and other cards were for me best choices and are best playable to me. Try and gg