243a0200_ne_Arena_Strategy___Blue_is_Me__Advantages
[Name] Wraith / Muta [Disadvantages] Bad versus anti air units such as Thor, Wraith, Viking or Goliath ,as well as psi-storm. [Advantages] 
They are air units, wraith is good anti air and mutalisk kill marines really well.
Starcraft 2: Marine Arena Strategy | Blue is Me
Advantages