Originally you were brought to my attention by the anti cheat being triggered for something that stuck out to me. So I entered vanish (making me invisible to players) and teleported to you.
I got round in front of you to see what you were doing and this is when you looked straight at me, I was very confused so to be sure I started spamming crouch to which you instantly started doing the same, this should be impossible, I double checked on my screen to see if I was definitely in vanish and I was, as well as then getting a player to make sure I was and they confirmed that I was.
I send a couple of messages though in global chat (to which you didn't respond to) and and apparent seeing me in vanish and triggering anti cheat was enough to warrant a ban to wait for an appeal.
You tried to join after I banned you so you should have been aware of the ban, as well as joining with an alt account earlier today which is not allowed (hence being ip-banned by infinite_mist) But you seem to not have been aware of the ban for whatever reason?
Taking into consideration, as you said, your time spent on the server (i have seen you around a lot which lead me to be weirded out by this) and the items you have at your disposal meaning you would have no reason for such things etc, I am willing to unban and give you the benefit of doubt and welcome you back. However I highly recommend not using clients such as Aristois because it has hacked features, which players have been banned for in the past.
I hope this has cleared up the confusion and you continue to enjoy the server.