Ricochet - who is the caster of the duplicate spell?

[Elemensch]

Is there a way to cause my opponent to be the caster of an effect targeted against my permanents?

Asking for a friend with a bunch of Graviton Salvagers.

[serprex]

Rico randomizes caster (mostly to balance rico PU)

Salvagers compare current turn to owner tho, so caster doesn't matter