I see, I guess the only thing that I am worried about is wasting money. I'm not interested in playing academy, all I have played is arena and that's what made me fall in love with the game.
I just remember looking through the academy spells and seeing spells that were pretty much better then dissolve and dispel but a lot cheaper. Do you think that this is a way to fix older cards?
First, as above, there are lots of cards in Academy expansions that are good in Arena. I'd be perfectly happy with my Academy "expansions" if I never played Academy. The fact that I've been playing Academy over lunch with work colleagues is a bonus!
Second, you can take a look at all these cards in the totally awesome fan-made unofficial spell book builder, here:
http://www.spellbookbuilder.comAcademy cards can be recognized in either fo a couple ways: (1) they always have the name of the school printed under the school symbol (e.g. where it tells you what level the spell is), and (2) this spell book builder allows you to choose what sets you "own," and if you turn off everything that
isn't Academy, then choose to only show cards you "own," you'll see all the Academy spells.
Third, Disperse and Crumble are not "pretty much better" than Dispel and Dissolve, respectively. They each cost 2 mana less than their Arena core set counterparts, but they're also FULL actions to cast. These cards pretty much declare that a FULL action has the same value as a QUICK action + 2 mana. Another way to think about it is that Lesser Teleport, which costs 2 mana, allows you to "move" as your Quickcast, then take a Full action - rather than move for free, then have the ability to cast 2 Quick-action spells. Moving your Mage or other friendly creature is worth about 2 mana... so the value of a Full action is about 2 mana more than a Quick action. (Force Push costs 3, but there are a lot of things you can do with Force Push that you can't do with Lesser Teleport, such as (a) move an enemy creature, (b) push an enemy creature through a wall with the "passage attacks" trait, (c) push an enemy creature into a wall without the "passage attacks" trait, including an Arena wall, making it suffer a "wall bash" attack, etc. ... so you pay an extra mana for that flexibility)
tl/dr: Disperse/Crumble aren't "better" than Dispel/Dissolve - and in fact, I rarely include these Academy cards in my Arena books, because I'd rather have the ability to move + melee attack, or double-move, or cast another Full action spell (like a creature) than get the 2 mana discount for a Full action Disperse or Crumble, with very rare exceptions... e.g. Mages that don't move very often, but also don't have much use for their Full actions; that is, Mages that use a Spawnpoint (or don't need many creatures), do not engage in Melee combat, and do not use Meditation Amulet - which is pretty rare.
*edit* There is another difference with Crumble. Crumble targets the Equipment, not the Mage, as with Dissolve. This means that Crumble gets around Nullify. However, Crumble can still be (softly) countered by Armor Ward, Arcane Ward (on the Equipment itself), Harshforge Plate, Anvil Throne "Runes," and Champion's Gauntlets, and Crumble still requires that the Mage casting it has enough mana on hand to cast Dissolve, but then gets a reimbursement of 2 mana... so it isn't quite as good as requiring 2 less mana in the first place (whereas Disperse really costs 2 less to cast).