As opposed to those higher tier opponents, Shiki is virtually undetectable because he has no power level. He's completely human and has few magic circuits. In addition, he seems to naturally have the ability to blend in with whatever static is around him, as Arcueid doesn't even notice him following her.
You won't feel anything, even when you're suddenly in 17 pieces.>>9424871
His knife is in front of him stuck in the ground, if that makes you feel better.