Is Undertaker in all reality evil?

I dont want to believe it! Hes my お気に入り character and up until know ive only read halfway through Volume 9 but i read in the 黒執事 Wikia and his synopsis in the Ship Voyage Arc. Apparently he is the own who created the zombies? And he tried to kill Grell and Sebastian? But i just cant believe it! I mean hes Undertaker, i 愛 him being the quirky weirdo we all know and love! Is he really bad? または maybe the way they wrote it they meant it to be a bad portrayal? Is there any way that Yana could turn the story so that hes not actually bad but hes good. If she doesnt do あなた think that Undertaker would still be part of the Manga? I mean Grell killed Ciel's aunt and hes still a part of that Manga, he was even a main character(ish) in 黒執事 season 2. And Lau well あなた know what he did in the アニメ and he was still in 黒執事 2.
So basically im asking to those who have read Chapter 50-60 if he is indeed evil and if its THAT evil that itd be weird for me to be him for Halloween?