Place this clip right at the summoning moment in your edit, just before your weapon barrage or power reveal begins. Follow it immediately with Nani Sore for the opponent's stunned reaction, then cut to your attack landing without any other sound in between.
About this sound
This is a short 2.3-second voice clip of Gilgamesh invoking his Gate of Babylon. It feels grandiose and intimidating, like an unbeatable king announcing a finishing move before the fight is even over. It comes from the Fate anime series, where it is his signature Noble Phantasm, a treasury that launches his legendary weapons.