Responding to Batterskull

[markbris]

When my opponent uses stoneforge mystic to bring his batterskull in to play, can I respond to the equipment attaching to the germ or is it instantaneous?

[Nihil Credo]

When my opponent uses stoneforge mystic to bring his batterskull in to play, can I respond to the equipment attaching to the germ or is it instantaneous?
You can respond to the Living Weapon trigger (e.g. by bouncing the artifact, which will leave the Germ as 0/0 and dying), but the Germ gets both created and equipped during the resolution of the same trigger. So you can't, for example, kill it with a Darkblast.