Dark Spirits (ダークスピリッツ) is the signature technique of Dr. Raichi in his Ghost Warrior state.
Dr. Raichi uses this technique to defend against the Z Fighters attacks against him, managing to repel the warriors, though they manage to break the barrier after several heavy blows and Raichi is dispatched by Vegeta's Final Flash.
Video game appearances
Dr. Raichi uses this technique in the Plan to Eradicate the Saiyans series of video games. The technique is named Dark Spirits in Dragon Ball Heroes.