Thank you! I'm afraid this is a problem of hints that should have told you when to use a magic attack or particles. In the first battle, mana falls on the field in the form of glowing particle balls and when they are taken and 20 mana is accumulated, you can use a magic attack by pressing the button E. 20 mana is 2 mana balls. The balls fall out on a timer about 10 seconds after taking the weapon.