>>7603980It IS zangetsu. Read the recent chapter.
Spoilers below if you are a newfag to the whole Bleach universe.
>Hollow Ichigo = Zangetsu spirit formThe hollow inside him was fused with his shinigami power when Urahara trained him to be a shinigami way back in the second season. The 'Old man Zangetsu' apparition is NOT the real Zangetsu, he is a fragment of YHWacH Quincy power posing as his main strength. The Ichigo's 'zanpakuto' that you see from the beginning until recent chapters is not a real zanpakuto at all, but rather, a spirit weapon similar to Quincy bow.
To sum it all, Ichigo's Quincy power is fucking him and all of us since the beginning, and his REAL shinigami power is suppressed by his Quincy power because YHWacH is a dick.
extra spoiler--- Final Getsuga Tensho is Ichigo's version of Quincy: Letz Stil.