I'm reading a manga about a person who becomes a bodyguard for the head of a Yakuza syndicate, due to various reasons including debt. There's a part where the body guard is being threatened after being kidnapped as bait, the real target being the kumicho. The bodyguard starts laughing after the kidnappers say that they are the body guard that the kumicho is most attached to/fond of, and so he will be disturbed and horrified from the bodyguard's death.
Then the bodyguard says: 「残念だったね 僕は彼にとってあく までも ただのボデぃガード．．．」
I know how to use までも with verb-ない form and I know までもない but I'm not sure what it means without ない. I tried to search for how to use it on grammar sites but everything had ない.
On a side note, I believe とってあく in this context (since there is no kanji to clarify) may mean "scum (that has been skimmed off the top of something)" but I am not sure. I looked in several dictionaries and also searched for related idioms, but was unable to find anything relevant.