Show: All formats Perfect Circle Edison
The cards sent to the Graveyard after the activation of “Full Salvo” are sent to the Graveyard by the effect of “Full Salvo”. They are not a cost. So they are sent when “Full Salvo” resolves, not when it is activated.
If you send a “Dark World” monster to the Graveyard for the effect of “Full Salvo”, its effects do not activate because it was not “discarded”.