The witches were born from the job that Razellia created, and their main power lies within their abilities to create several different potions that are dearly needed for the world to function now.
The main source of power behind this job is the element of destruction, a gift from Razellia to all her followers. Of course, none of them receives its full power, just a small fraction, enough for the witches to destabilize the materials and create their potions.
But this does not mean that it's good and bright for all the witches. The power they receive has its downfall as it creates a layer of destruction capabilities in their bodies. Due to Razellia's past unhappiness and pettiness, she made it such that those who take the path of the witch would lose their ability to fall in love. A price that depends on perceptions can be seen as something insignificant or something too hard to give up.