This is a follow up to a previous question: How could mages regard fast magic as a form of evil?
There are 2 forms of magic in this world, the first of which is white magic, which is performed through a series of steps. A mage sits in the center of a drawn invocation circle, surrounded by the various ingredients needed to perform the spell. The mage then utters the incantation, which can take anywhere from minutes to hours depending on the spell. The gods, being universally worshiped in the world, are morally ambiguous when it comes to magic. There are spells which require harmless ingredients like eye of newt, and there are spells that require the body parts of recently killed children. The latter is thrown into the category of "black magic". Either way, the gods are indifferent to concepts such as good and bad. The second form disregards invocation circles and the use of ingredients, simply depending on incantations to perform spells. It is therefore a quicker and more effective use of magic, saving time, resources, and expenses. however, it is regarded as evil due to the fact that it comes from devils of another plane, and ignores the rituals of the gods ( ingredients, circles, etc).
Since the first form of magic is slow, it is very inconvenient when going up against a dark wizard. The latter would wipe the floor with them in a confrontation. Therefore, evil magic will always defeat good magic. What advantage can slow magic have over fast magic that would give them a chance of winning?