THE SLOW LIGHTING : Black Flash can use Phasing/Teleport. Black Flash modifies his attack value by +2 if the target of his attack has a speed value greater than or equal to Black Flash.

He has this on the same click as hypersonic speed, so he can use both? im asking because both are power action.

Oh, another one on teleport: it says that when carrying another character, the character using it can go through blocking terrain, but may he/she go through walls too?

Looks like you posted in the unit section feedback instead of the rules forum.

But to answer your questions, no a character cannot use Hypersonic Speed and Phasing/Teleport together. Like you said they both require power actions.

A character with both the Carry ability and Phasing could carry another character through walls, blocking, etc. However, Black Flash does not have the carry ability. If Black Flash somehow gained the carry ability, for example, through the feat Passenger, then he could carry another character through blocking terrain.