So it is likely that youkai can't be killed simply by attacking their bodies. And something taking over/attacking their minds would be similar to death. The core of a Youkai isn't it's physical, but its mind. In other words, rather than being reborn, the spirit will take over their entire existence.
It seems that youkai normally can restore their physical bodies if it is destroyed, although it is hard for beasts to do.
*Youkai have stronger bodies than humans, so even if they're split into five parts, they heal right away.*Youkai have longer lifespans than humans.
#TOUHOU URBAN LEGEND IN LIMBO PHYSICAL COPY SERIES#
Youkai have some notably specific characteristics in the series instead of being just generic baddies. Youkai are being created from an unknown phenomenon, stated quite a lot on Touhou Suzunaan, they're super strong and can regenerate in an alarming state. This section will explain characters physiology, thus anyone that fall under these races will have their physiology automatically. 2.15 Watatsuki no Toyohime and Watatsuki no Yorihime (The Watatsuki Sisters).