The master property

Answer from: Haizel
Mastery means you know better how to use a certain element. If your pet attacks with fire, you want Fire Mastery to do extra damage when you attack.

Bane means you're more deadly AGAINST another element. Use one of the elements your pet is already strong against to do massive damage. If your pet attacks with fire, get Grass Bane or Elec Bane and watch your pet do ridiculous damage to those kinds of pets.

Resist means you're stronger against a certain element. Use one of the elements your pet is weak against to prevent massive damage. If your pet uses fire, make sure it has Water Bane and Earth Bane.

Remember the Element Wheel:
Fire beats Grass and Elec, but is weak to Water and Earth
Grass beats Earth and Water, but is weak to Fire and Wind
Elec beats Water and Wind, but is weak to Fire and Earth
Water beats Fire and Wind, but is weak to Elec and Grass
Wind beats Grass and Earth, but is weak to Water and Elec
Earth beats Fire and Elec, but is weak to Grass and Wind
Primal does regular damage to everyone, but has no weakness either.

Answer from: Derek
Oh okay, thanks. That's what I thought, but when I got two different masteries on my weapon it made me curious.

Answer from: Pokeluigimon
ATK and MTK addition and ATK and MTK gift are 2 times more powerful than using master property. I tested. I had 1 account with LV9 Fire master property and LV6 attacks. And my other account had LV9 ATK addition and LV5 attacks. Don't use master property, it's not worth it.