Tanaka wasn't the only servant the Phantomhives had. They had a whole house of servants before the attack. They all got offed the same night the twins got captured.
I posted a theory that Polaris is one of those servants. If you're curious, check it out.
Yeah I known they had a lot of servants but there was only one butler (we only know about 1) Tanaka, Yana sensei wasn't mention any other butler except for Tanaka and Sebastian of course (+Agni) and that guy "Polaris" said that he will always be a butler even in death
Tanaka was the house steward in Vincent's time, not technically the butler. Before the attack, there was another head butler. He was unnamed, but he existed. Check out chapter 151, there's a page where Tanaka counts off the house staff of the manor before its attack. There's a head butler guy there that isn't Tanaka. Plus, the same guy also cameos in OCiel's flashback, both as a servant and as a dead body.
I felt the same way! Maybe it's that guy our Ciel tripped over.
Wait a sec that "butler" said that he doesn't want to lose him one more time (RCiel who is Serius) so was he a butler to phantomhive manor? I thought was only Tanaka