Why? He is a historical figure. Why does a historical figure in his historical setting feel bizarre?

Why him being a “full fledged samurai” even matters?

This is just difference in opinion. For you it’s OK. I get that this series is only very vaguely based on history but this is a step too far for me.

Seriously ask yourself why having ONE SINGULAR black protagonist in a series where protagonists have so far been overwhelmingly white

Why MUST they make the main character in a 1580’s japanese setting black? The series hasn’t had a single asian protagonist. Couldn’t they have chosen a black history setting if this is what they wanted?