Always tough to say frmo pics alone, but Efflatounaria is really odd among Xeniids and this looks nothing like it (many folks says Efflatournaria looks like Cladiella/Colt corals... they do a bit)
This coral has a hint of possibly being Cespitularia, but then again... if yours pulses and does not have white spicules that reflect silver (see my Cespitularia article in the archives here)... then you likely just have a nice bluish Xenia species.