As is known, and mentioned by FFS, Alternative battle systems require a requisite amount of soul charge to be utilized.
DANCE OFF TIEM!
Good idea, +1 to dance battle if we are forced into battle after attempting to speak to him.

Your CHARGE is too low to utilize any ALTERNATIVE BATTLE SYSTEMS!
Tactical combat is of course, a form of alternative combat; meaning it requires soul charge to be activated; although for tactical combat, the amount is miniscule compared to other forms. As evidenced by the lack of noticeable change in soul charge.
As shown by Yaos, when someone loses Soul Charge; they experience slight to extreme pain when the charge is taken away; Tactical combat however, took away such a small amount of Charge, that Ciro only had to experience bleeding once, but it was minor.
Also, because we had a decent amount of Soul charge, we had almost no pain at all
So as to summarize,
Miniscule soul charge taken away, due to ALTERNATIVE BATTLE SYSTEMS, caused slight bleeding as a side effect; as seen by Yaos.