I was looking at the spell descriptions today... and I saw something kind of shocking... but yeah...
Burning Blood is the most damaging single target spell in the game... assuming nothing impedes it and you have the correct feats and enhancements and items.
Why?
Extend Spell.
Burning blood deals 1d8 fire and 1d8 acid damage every 6 seconds per caster level.
Now... here's where it gets interesting... you can apply maximize... empower... AND extend to this spell.
So, let's do the math for the spell alone... at most for a 16th level caster (without any feats or enhancements), burning blood would do 256 damage.
Now, let's apply potency and enhancements (for both fire and acid)
So 50%(128)+40%(102)+256=486... now... we maximize it... so 486+486...=972... and we empower it... 486*.5=253.. 972+253=1225
Now we get to the REALLY juicy part...
Extend Spell... which effectively doubles ALL the previous damage because it doubles the duration.
So without ANY crits... 1225x2=2450...
Two thousand four hundred and fifty damage max at level 16.... or an average... again, without crits... of about 1225.
With Crits... well, yeah... you get the point.