There is a hidden rule for all mages that is to jump every time when casting a lightning spell to prevent self electrocution, how this work is as follows:
First the mage recites an incantation to transform their body into a meat vessel to act like a capacitor to store electricity, the only indication of saturation is the tingling sensation and hair raising up. When it is about time to cast the lightning spell, the mage has to jump high in the air and commands the power of lightning to flow towards the target. Failing to make the jump while the spell is active will cause the vessel to discharge through the legs and result in severe burns or in the worst case scenario death!
No footwear because the vessel is siphoning the electricity from the ground while having to make sure the current is tolerable by focusing deeply, however there seems to be an exception to this. There is a particular mage who doesn't seems to have to jump to cast any lightning spell, in fact this mage is the only mage in history to be able to do nested casting! It just means casting multiple spells at once but the level of concentration is absurd with just one spell let alone two, I am wondering how does this legendary mage managed to pull off this feat without getting self electrocuted?