Your opponent cannot target Level 6 or lower "Artmage" monsters you control with card effects. You can only use each of the following effects of "Artmage Finmel" once per turn. If you control an "Artmage" card: You can Special Summon this card from your hand, then you can draw 1 card. During the Main Phase, if you have 3 or more different Monster Types on your field (Quick Effect): You can negate the effects of all face-up monsters your opponent currently controls, also until the end of this turn, their ATK's become halved.
