Broken Phantasm

Broken Phantasm (壊れた幻想) consists of packing a Noble Phantasm with prana and making it explod when striking the target with it.

By nature, it's not easy to repair a Noble Phantasm destroyed that way as a Noble Phantasm is part of the Heroic Spirit who has lived with it, so it is seldom used as it can be done only once; but for Archer, as long as he has the prana, he can still keep reproducing copies of the destroyed Noble Phantasms through Tracing, so this limitation doesn't apply to him. Therefore, you may call it a foul play he can afford.

It is the destructive power Archer used in the ambush attack on Berserker.

Source: based on the Tsukihime Laboratory entry and the dictionary resource at Jonnobi.