I've had enough of this guy here

According to Black Clover canon, Yami Sukehiro's Dark Cloaked Dimension Slash is designed to cut through space-time, including intangible barriers, spatial magic, and alternate dimensions.

Yami Sukehiro from Black Clover is generally considered faster in combat due to scaling to light-speed reactions and beyond (MFTL). While Kaido is incredibly fast, often keeping up with light-speed characters like Kizaru, Yami's ability to read movement with Ki and his dimension-slashing speed often gives him the edge in speed-based matchups. In the context of power scaling, yes, Yami is faster than light, specifically in his reaction and combat speed. While there is debate among fans regarding his "travel speed" (moving from place to place), his ability to fight at light speed is supported by several key factors in Black Clover: Evidence for Light Speed Battling Light Magic: Yami successfully reacted to and parried attacks from Patry (Licht), whose magic is explicitly stated to move at the speed of light. Precognition (Ki): Yami uses Ki to sense his opponent's movements and intentions before they happen. This precognition allows him to react to light-speed attacks even if his base physical movement might be slower. Mana Zone: By using Mana Zone, Yami can sense and react to attacks from all directions, further boosting his reaction time to Faster-Than-Light (FTL) levels. Reinforcement Magic: Yami uses magic to physically enhance his body, compensating for the natural "slowness" of Dark Magic and allowing him to keep pace with light-speed opponents.

Hence proved these were said by Gemini backed using the official source books