I was using Mothstem cards with my wizards up to recently. With three level 10 cards you get +210 matk. However, the more the game advances, the more matk is boosted on weapons, which means that the effect of the flat cards becomes lower and lower. When you’re using Velco Rod T10 and your base matk is over 10k with that rod, the 210 matk you get is simply not worth it. That’s why I replaced those cards with 3x level 10 Chapparition to get +30% damage for 6 seconds after quaffing SP potion, which means 40% of the time, since alchemist potions have a cooldown of 15 secs. That’s a theoric 12% boost, while the Mothstem would only give 2%.