From your given set
Item: Sash
Timid Nature
252 Sp.atk/252 Spd/4Hp
ability: Synchronize (most likely ability)
-Signal Beam
-Psyshock
-Shadow Ball
-Dazzling Gleam
I chose dazzling gleam because espeons move pool is fairly limited(only learning special attacks from psychic ghost bug grass fairy and normal) and its got pretty good bp.
Grass Knot is another good option covering water and rock type attacks
Finally Hyper voice is viable for its high bp but doesnt really help type coverage wise