
How can the saintess use holy powers when she's a vile creature with dark as coal malice running in her veins? hahah

Well, depending the world, holy can be in fact light magic and light magic is not necessary magic that can only good people can use or make a.person a good one. The same with dark magic, dark magic doesn't means the person is evil or need to be evil to use it!
Alao it depend who is the godnthat gives that holy magic!!! It can be an evil god!!!
I'm scared of that slimy brother.