The Shisui of the Violet Tides quest ends with an acknowledgement that not a single life was lost, so it is safe to assume that, however improbable, not all acts of player-controlled violence (at least from Stormblood on) carry the intent of lethal force.
Quote Originally Posted by Kurenai
You may be happy to hear that the palace guards are all slowly beginning to return to their senses. It seems peace has finally been restored to the palace.

You have saved everyone, including Shiosai, from an untimely death. If only the Ruby Princess would open her eyes, Sui–no–Sato will be exactly as it was before.
But if you mean the literal mechanics of how mineuchi is supposed to work with giant deicidal fireballs... I might invoke the MST3k Mantra on that one.