If Bloody Slash banishes a SIGNI that would leave the battlefield as part of a condition for a spell's effect to fully resolve (such as through SPRASH or Get Index), then the spell's ability does not resolve.
However, Bloody Slash has no effect on spells that change a SIGNI's status as part of its cost (i.e. Soap Sudden).
If Bloody Slash banishes a SIGNI that is about to be put into the trash as part of Lost Technology, Lost Technology's owner may choose to not put any of their SIGNI into the trash upon resolution.
If you use Bloody Slash during your opponent's turn and send 1 of your SIGNI to the trash, then banish your opponent's Vier=Rikabuto, your opponent does not put the top card of their deck into their Ener Zone.
