So as anything I've ever theorized for bleach, im wanting to purpose that ichigo is a being of true and purest power.
ichigo naturally is to be cloaked in power, be physically strong, fast, and have a basic blast abilities, where the main variations are just a matter of intensity. I suggest the solution to the representation of powers that he does have.
he is human with spiritual back grounds, and im not talking about just his father, im talking about being able to interact with spirits. as to why it probably is due to his father but this ability is only to lead to the "blossoming" of his other abilities.
he interacts with a shinigami, this isnt a big deal but it becomes one when that shinigami gives him power. abilities grown and adapted to the situation.
he killed and fought hollows, i think at this point his hollow self was beginning to manifest, tho not expressing itself until he is forced to acquire his powers again and awaken the monster that is in him. this stage was very unstable.
He goes to the spiritual world where he fights many people stronger then he, but seemingly is able to topple, and even become much much stronger then any, almost each and every time he fought, no matter how much power was exrpessed against him, it would only make him grow to express more. his shinigami stage is becoming more and more developed, but his hollow stage is lacking hollow interaction and so is only able to grow in a very simple but effective manner. however hollow self is increasingly unstable.
aizen is found out. ichigo must encounter being that are no longer purely shinigami (vizards) or hollow (arrancar) the former showing to him a manner to control ones hollow self. something to note here is that ichigo IS NOT a vizard. vizards where experiments, where as ichigo was a natural means for a human to acquire similar powers. the latter of the two (arrancar) showed ichigo a control of the rampant power in a different way, and so his hollow abilities grew and began to balance out more or less with his shinigami powers.
another note: ichigos power advancments generally where advanced while challenging or being challenged by others with similar powers.
aizen fight. the final getsuga is an instant expression of all his powers thus far, and an expression of the powers against him in terms of his own powers, in turn for a "system reset".
ichigo loses powers but gains new powers and only expresses those new powers ( which fundamentally are the same powers but with new "core" which was fullbring) ichigo is not a fullbringer as he does have the initial cause to becoming a fullbringer. he just replicates the power in his own terms.
He loses those powers, but not to long after is given his shinigami powers again in the same manner he got them, but just more. his shinigami abilities are better then they where before but we haven't seen his hollow powers. reason being is he hasnt had enough interaction with hollow like being to redevelop them. however he does still have fullbring powers as he is still in combat with them, and not all of it was taken. thus fullbring powers and shinigami powers are blended together
one can theorize that his fullbring powers are a re-expression of his hollow powers tho in a much more stable form.
with his powers as basic as they are, he is a being that can only express power in similar fashions to what he has encountered/ or fought. when powers are lost he is able to awaken a new and stronger form of what once was his powers.
I think that this new arc will give ichigo a chance to redevelop his hollow powers even more in to a more stable form. the quincy seem to be well organized and controlled, and i believe that the more we see of them, the more this statement will be confirmed, and ichigo powers will develop in kind.