As expected, most students had chosen to add three enchantments to their weapons as was the limit set by the professor, overseeing the fact that the smaller one's mana pool, the harder it was for them to maintain these three enchantments… and several other precautions.
Different enchantments had different mana requirements as well. Some required a small amount to keep working while others required a gluttonous amount of mana to keep functioning.
And with three enchantments embedded into a single weapon, mana would be drained nearly instantly if all three enchantments were activated at once.
That said, this concern went to those that had small mana pools. As a default, anyone that failed the Warlock Sorting test fell into this category.
Since Warlocks solely depended on their mana pools to be useful in battle, there was a limit to how small one's mana pool could be before one could join that course.