Ok some people dont know this but there are some classes that are very rare and are A LOT STRONGER than the others For example:
Samurai
Paladin
Ninja

This classes can be achieved by swapping djinns where is the reciepe for the samurai class best done on Garet or Isaac which has A very strong attack called quick strike that can deal damage (at least in my lvl 40 felix)like 400 and just takes 12pp away.

Samurai or Ronin

5 earth 4 wind

Ninja or Disciple

use on Felix or Jenna

4 earth

4 wind

Paladin

4 earth 4 water

and a good one Chaos Lord

2 fire 7 earth

ENJOY ( there are more though work to discover them)