Who you really are, is an immaterial soul and the body is an external thing that's sort of an encrustation your soul. So this has important implications for Plotinus' ethics, because his ethics are basically all about encouraging us to turn away from the body and turn towards these higher principles, so universal soul, universal intellect and ultimately the One.

Basically the problem is that if the intellect is looking at or beholding the forms, what it will get is some kind of representation or image of the forms, but it won't actually have the forms, it won't touch them as it were, or it won't incorporate them.

Plato in his dialogue The Phaedo says that whereas sticks and stones are both equal and unequal, (so maybe what that means is that each stick is going to be equal to some other sticks and unequal to some other sticks, so equal to the stick on the left maybe but shorter than the stick on its right) the form of equal is going to be just equal, and it won't partake of inequality at all. And it will be the cause of equality in things that are equal, for example, equal sticks and stones.

For Plotinus, what really exists are the Platonic forms, so the true nature or form of things like justice, beauty, maybe numbers, things like that, and these he associates with the intellect because they're the objects of intellect, they are things that intellect can think about.

The soul must be distinct from intellect because even at its best, what the soul does when it's thinking, is it thinks linguistically, it thinks in a temporarily extended way, so it for example, might go through the steps of an argument chain, as if you were going through a syllogism and seeing that something followed from the premises, whereas intellect simply grasps the forms.

Assuming there is an intellect, we're clearly not this universal intellect or we would know it. So that's one function of soul.

The importance of Plotinus is not only his own philosophical ideas which are quite interesting, but his historical impact as the founder of neo-Platonism which is the main philosophical tradition of late antiquity.