A l i k e s ;
TAITO MAGATSU
I'm telling you, these two have been separated at birth. First of all, their names are almost identical. Second, they've both got that funky hair thing going on. :) Also, they're both baddies (although in the comic there aren't really good or evil, just opposite sides), they both have dirty fighting styles, the both wear a mask of sorts and they've both gone through some hard stuff (Mugetsu had that lobotomy done on him, Magatsu's lost first his little sister, then his lover). The only major difference is that Tai-Tai is sane. And his hair is a BIT wilder than Mugee's. XD
Magatsu is a character from Blade Of The Immortal, a manga by Hiroaki Samura.

DILANDAU ALBATOU
Dilandau isn't that much of a look-a-like (except for the color of hair, maybe) but is similar to Mugee in personality. Just like Mugetsu, Dilandau is clearly very deranged, homicidal, quick to anger and ready to do anything to accomplish his goals. They both seem to love fighting and are obsessive when it comes to defeating their enemies. Also, dilandau was used as a guinea-pig for the fate-alteration program of the Zaibach, the country he serves - much like Mugetsu was used by the Mikado - and the results were very tragic and traumatic.
Dilandau is from Vision Of Escaflowne, a tv series and movie.

TETSUO SHIMA
Aside from spiky hair, there isn't much resemblance between Tetsuo and Mugetsu look-wise. But they both are aggressive, a tad (cough) screwed in the head and neither of them will let anything or anyone stand in their way. Tetsuo used to be just a normal boy - as did Mugetsu, without a doubt - but the sudden gain of power turned him into a murderous monster who would take his revenge on anyone who used to mock and scoff at him for being weak and small - even his best friends. Maybe it was the same with Mugetsu. Maybe. But things go horribly wrong, just as with Tetsuo - he can't control his power and is constantly tormented by his own insanity and memories.
Tetsuo is a character from Akira, a manga and anime by Katsuhiro Otomo.

KAKASHI HATAKE
Being rather laid-back and nearly always late (!), Kakashi often appears goofy, but he should never be underestimated - he's one of the most skillful ninja of his clan, having mastered over 1000 Jutsus (skills, spells).
Not alike personality wise, Kakashi resembles Mugetsu in appearance - at least a litte, as they both have white/silver, spiky hair. Otherwise it's a little hard to tell as Kakashi's always masked.
Kakashi is a character from the manga series Naruto (now also an anime series) by Kishimoto Masashi.