>>19637
Tohno can in fact kill servants.
When he killed Arcueid, 17 cuts landed in "an instant".
This is on the same level as 5th grail war Asassin's Tsubame Gaeshi. This is in fact canon. Not only that, but Arcueid was not able to notice she was being followed, nor feel any killing intent from Tohno until the blade already killed her. This is on the same level as assassin servant presence concealment.
In the official Tsukihime manga, Shiki was capable of slicing and killing lightning shot at him by Roa. A low estimate of the speed required for this would land at 96,000MPH, which is the atmospheric discharge of lightning at denser levels (closer to lower altitudes.)
Tying together presence concealment, Zelretch level ability (flash sheath), and A class speed, Shiki could in fact stand a chance against most servants. His trump card that would place him above anything summoned under assassin card would be that he essentially has an instant kill move if he ever gets near, making him a very deadly opponent.
To use concrete evidence of Shiki proving himself time and time again, we can look at who in fact he has killed.
Nrvnqsr Chaos the 10th apostle. In one attack Tohno managed to kill all 666 of his lives.
Michael Roa Valdamjong, said to be immortal by traveling between Akasha and back, "reincarnating". Tohno severed his connection to Akasha, erasing his existence.
It's good to take note here, that Servants are tied to the Akashic record in the throne of heroes, which is what allows them to be summoned in the first place. When Shiki kills a servant, they can no longer be summoned. Sounds like just the kind of person Archer was looking for.
In the "Talk" side story for Tsukihime, Tohno manged to kill the forest of Einnashe, the seventh dead apostle. He also managed to kill Einnashe's reality marble.