Currently the only build which actually synergizes with itself is pure mage, and it synergizes SO HARD.
Um, everything halfway decent has a cooldown of at least one turn. So it has to synergize; otherwise, it would always feel like you're using your AP in a suboptimal way after you blow through your best cooldowns. This effect is felt a little anyway, but a feeling of synergy is the thing keeping it from feeling like shtuff.
The advantage of the other classes isn't synergy, it's raw power. It's about taking a relatively simple concept (attacking), making it awesome, then repeating that awesome multiple times in one turn. Synergy is overrated.
