If you consider Magatsu(esp once you get to around vol 12) then think about my various faves, you'll notice a lot bear some resemblance to him in personality-hotheaded, hero complex, devoted to a friend first and foremost, striking up odd quasi-friendships with enemies, knight in shining armor complex, vengeance quest, etc.(and his hair and mask have spawned a few similar characters)

Similarly, a number of the heroines I latch onto the strongest have similarities to Rin(Yuya being the only one you're likely familiar with)