After repeating the same drawing nearly twenty times Eris nodded satisfied with the result, for a rune to be effective the lines needed to be clear and well defined, or the effect would end up being poor.
"That's enough, now just use your soul energy to activate the rune, first try with one of your early designs".
Aster did as she told, his soul avatar inside the mind space glowed and the draw illuminated, but instead of activating the rune, the paper burned itself.
"That in one of the most common mistakes among new rune masters, when the lines of the rune aren't perfectly defined, instead of activating the effect outwards, it activates inwards, that's why the paper burned instead of producing fire".
Aster nodded, he then tried to infuse his soul energy into the last rune he drew, the paper illuminated and after a moment a wisp of flame floated above the paper for a few seconds before it dissipated.