This spell seems to do different amounts of damage to different people.

For example, when I use it against Riften guards it does about 15-20% of their health per second. But against some random bandits it does a lot less.

This doesn't seem strange, but when I used other spells such as fireball against those two enemies, it does roughly the same damage. I am testing this on the same bandit, it's a fair test.

Just seems sometimes the flame cloak spell does a [censored] load of damage, others its quite average. Does anyone know, or can test this out using the console etc?

Fire resist?

The fireball spell does roughly the same damage to each of them.