I would propose to you to buy none general, basically none general will help you bounce anyone.
As Elandal said maybe Daphne to reduce the speed of your death in guild battles.
You said it above yourself, when you equip Sahar you bounce peeps.
Keep it that way, continue lvling your 3 strongest generals stats wise, i assume they are Sahar, Barbarus and Dolomar. Having their alliance when defending will help you much more than Katherine or Celesta or anyone else.
Btw i bet that if you leave your highest stats general equipped with gear with resistance there is no chance lvls 25 will beat you.