In the good ol’ days, ninjas were renowned for their ability to make impossible climbs. They also bumped people off for money, so they weren’t the good part of the good ol’ days. However, cats climb even better than ninjas and they don’t bump people off, no matter how much Fancy Feast you offer them.
A word to the wise: you might want to reconsider allowing that little kitten to shinny up your leg. When he grows up, that’s gonna hurt a lot.