Dark Phantasm is a Sealed Verse in Nier Replicant and NieR Replicant ver.1.22474487139.... Sealed Verses such as Dark Phantasm are special abilities used by Grimoire Weiss that assist NieR in battle. They can be unlocked by progressing the story and completing content.
Dark Phantasm Effect
Dispatch a magical doppelganger to attack nearby enemies. Charge to increase attack range.
Dark Phantasm will be a great show of magic followed by a large radial outward blast from NieR sending a dark shadow copy NieR that swiftly obliterates enemies within range. You will notice the range of this power with a glowing ring around NieR. NieR becomes invincible for a short period during this attack, and a good benefit of this power is that if it didn't detect any targets within range while it is used, the MP meter is restored. Charging this attack will also increase its range, including aerial enemies. This attack is ideal with NieR is surrounded by Shades.
Dark Phantasm Location