I gotta disagree with you. Isshin must have his shikai out. How could he use Tetsuga Tensho with an unreleased sword?
Originally Posted by Hikaru
Not to ruin anyone's parade but ichigo is one of the weakest if not the weaker of all the good guys, every single win up to this point has being due to PNJ and not to his skill.
Lets recap ichigo abilities, he has 1 skill(Tetsuga Tensho) he needs his Bankai to keep up with other people shikai and needs a mask to somehow keep up with their bankai, and even with the mask on he falls short and only wins because no one takes him seriously so they toy with him until Kubo pulls a fake rabit and makes ichigo win by force of plot.
Ishiin with only his UNrelease sword(not even Shikai in case you didn't get it) is keeping up with Aizen and is able to "FLICK" aizen off , remember that Ichigo with Bankai couldn't even touch Aizen and got Owned bared handed in the SS ark.
So anyone that puts Ishiin and Ichigo on the same level(or call Ichigo stronger) is seriously just 1-) on crack or 2-) has been reading a different manga than i have.
Other then that I agree with the rest of your post (more or less) Isshin>>ichigo at base. But IMO ichigo with his mask is about the same level as isshin at base.
So far we haven't seen enough of isshin to determine his full strength, but it's hard to imagine he would be stronger then ichigo's full hollow mode. Anybody that strong could have taken care of Aizen years ago, before he got his magic stone.