just some help for the newer players to the game
-This is from my knowledge so feel free to correct me anytime-
It's very simple, there are two different area's of damage dealing, magical and physical, your monster may have strong MATK (Magical Atk) or have strong regular attack, AKA ATK. So be careful when you go to teach your meniss Tsunami or your Lupa Avalanche, make sure to check out if your monsters is good in MATK or ATK, then click on your skill book in your bag and it should say magical or physical.
Thus concludes my topic =)
I just did this topic because I taught my Lupa hot smoke which is physical and wondered why it was not dealing much damage, also did the same with tsunami and Meniss.