Similar to tempest hydro has a specialty of rank X AoE spells here is the list: Hydro blade earned by your professor at level 2, 30+ damage [not all spells are rank X spells and AoE's]
Mystic waves [earned at level 5]: deals 35 damage per pip AoE
Water whip [ earned at level 10]: deals 380-400 damage
Kappa [ earned at level 25]: deals 575-650 damage and gives a random charm to you
Furious Tsunami [ earned at level 40]: deals 100 damage per pip AoE
Notice half of these spells take a while to learn? its because these spells are strong they dont have a lot of spells like the others and it takes long to earn them.
Tempest is the Pigswick version of Storm; therefore, Hydro is pretty much Storm.
Yes, very true. And we all know that Pigswick students aren't really that good of wizards. They even admit that, as in the library it says "Most Pigswick students do not grow up to become actual wizards". Of course not word for word, but close. Besides, it sounds much too much like Hydra, and really is just Storm.