With a normal spear, Theron could probably only split it two or three ways before he risked permanently damaging the blade. After all, Dark Mana didn't teleport—it deconstructed and then reconstructed. If he used it on his own blade, he would be effectively dividing its power and allowing enemies to attack it at its weakest points.
However, with a spear as powerful as the Nightingale Ancestor Spear, it could even be split upwards of half a dozen ways without issue. If Theron's Dark Mana was more powerful and he could protect the blades more, or even reinforce them more, going upwards of a dozen split attacks at once wouldn't be an issue.
In fact, it could be said that the only reason Theron was limiting himself to half a dozen was because he was being conservative.
Normally, a blade like this couldn't be so easily deconstructed in the first place. The only reason it could be was because it had become an extension of himself after refinement.
