BloodRain
Knight of Retribution
Apparently he made his robot/doll crush Hazama's throat in 0.00000208333 seconds or something, which would put him at 480,000m/s or Mach 1,411.
Problem; There's nothing to even suggests that Relius needed speed for this. People say that he timed his attack in this split second, when all that had to happen was for Hazama to die so that he could time his transition to that room. No reason to think that Relius had to do it in that moment, and even if he did, all it took was great timing. Reactions maybe, but speed isnt needed.
However whether his speed is superhuman, lightning or Ma1,411.. its all going to be heavily crippled by QS.
Though even if Dante can control the balance of speed theres still the issue of damage. Relius may be physically weaker than Dante3, but he's still a Large Building buster with City-Block durability. While this would be no problem for any other version of Dante, DMC3 Dante only has Small Building busting force with Large Building durability. It could be argued that he could go DT to close up the DC and Dura gap to a more equal level, I mean technically all he would have to do is match Ragna's DC to be able to pull a win.
[Ragna's a Large Building buster and was able to beat Hazama after all.]