Regus bet big on the Surya-Astra's top-move, the [ Solar Beam ] to turn the tide of the battle in his favour.
Solar Beam was one of those moves that was near impossible to avoid as it came down upon oneself at the speed of light.
It was extremely difficult to detect, much less block or evade and even Dracula with all his thousands of years worth of battle experience did not have an answer to it.
*BOOM*
Left exposed to the full might of a solar attack, Dracula felt his heart skipping a beat for the first time in over five millennia.
His body was hurting all over, his skin burning and fading away as he genuinely questioned his ability to survive the assault while tempering through the horrid experience with grit and unwavering resolve.
At this moment he acknowledged Regus, if nothing else the Vampire King was tenacious and a worthy adversary.