Is there a significant difference between different combinations of spells in Fable 3? I've found Shock + Vortex to be satisfyingly destructive. But are there better combinations? Do some combinations get bonuses, or is it a matter of taste?
Vortex fits with everything, really.
Fireball and Blades give the most damage.
Snow Storm is also a very good spell to combine with Vortex: the combination makes the spell duration four times longer and is very effective for both targeted and area casting.
The best combinations for me are:
Vortex + Snow Storm (Damage + Stun + Very Long Duration/ Large Area + Targeted = 4x Area)
Vortex + Blades (Damage + Stun + Long Duration/ Area = 4x Targeted)
Fireball + Blades (Massive Damage/Targeted)
Fireball + Force Push (Large Damage/Targeted + Area)
Never combine Snow Storm with Shock, Fireball or Force Push though; these combinations suck.
Fireball + Shock is what I always used. It looks neat and it pretty much destroys anything when fully charged. Use it when you are surrounded by a lot of enemies. Not only does it cause considerable damage, but also stuns them for 4 seconds or so, allowing you the time to safely charge up another finishing blow.
I found Shock + Vortex and Fire + Blades to be the 2 greatest combinations. Personally, I use one that "fits me", which is Vortex + Snow, though I don't know if you would like it, so I won't say it's the "best".
Either way there is no such thing as the "best" combination of spells. It depends on what you like most. Damage? Fire + Blade. Duration? Vortex + Snow. Both? Vortex + Shock. Try them all and see which one fits you best.