question for engineer pvpers

i was in a match earlier and an engineer seemed to kill me with one skill or just looked like it . i am not sure what it is called i guess you could say it looks like a virtual fence in the shape of a Circle about the size of a point. i have seen them before but i never had one drop while i am in it. i was hoping someone could tell me what that thing does

Hard Light Arena, it Gives boons to the Holo while hes inside of it, but thats all, that Skill deals no damage whatsoever.

Whatever it killed you it was another Skill, not that one.

Probably ran static discharge and blasted his tool belt skills on you while using photonic module detonation or while using a burst skill, or maybe was just the module detonation its situational but hits like a train