As a friend of OP I'd like to offer some small input. I have many friends that play this game that are regularly abrasive and unpleasant to play with, perfectly fitting the community's definition of toxicity, who I would not defend in a case such as this were they to get permabanned.
Some of OP's names were really inappropriate and offensive but they have never been malicious or hateful in intent. My friend has a very dark sense of humour and it's never seemed to bother other players in the game from what I could tell - at least not enough to earn some sort of comment or rebuke. An examination of the present circumstances would demonstrate how wrong I was. But surely if the only major infraction he's committed over the course of years was to express his poor sense of taste, thereby offending others in a rather mild fashion, is he really deserving of a permanent ban? Is this really consistent with the intent of the rules we use to regulate community behavior by?
I'd like to emphasize the fact that, though he changed his name numerous times, there was only a single occasion where taking this action was actually prompted by Riot. Only once was he given any sort of feedback or input from Riot and the community that informed him that his behavior had crossed a line. No temporary bans, no chat restrictions and no warnings were given. Yes some good sense would tell anyone that a name like IsisGankedParis is going to offend some people, and I'm sure he knew that. But his propensity for a more risqué sense of humour tends to overpowered his sense of better judgement, especially when you consider that, in the context of an online video game, such jokes are rather commonplace.
One might argue that such humour falls under the umbrella category of what is considered toxic behavior in LoL, merely because it mildly offends and makes the game slightly more unpleasant for certain people. Toxic behavior too is rather commonplace in online videogames, to the point where it is even accepted and even celebrated by some parts of the community. I would like to state first that I do not take that stance by any means. I have despised such behavior since I have started playing this game, and I have always striven to improve my own behavior in the face of such unpleasantness. However I argue that this sort of humour is rather distinct from the set of behaviors we generally regard as toxic. This humour is also accepted and shared by many parts of the community, although Riot seems to have deemed it inappropriate, And perhaps it is too inappropriate for an online game with an audience of diverse sensibilities. I would disagree but that's not my decision to make.
What's in a name though? Is a name going to ruin the game for me? Maybe for some it might, though I can't imagine who. I can recall countless situations where players have verbally assailed me using language more colourful than a Jackson Pollock painting though. Some of them for a while were even on my friend's list, at least while I could still tolerate them attacking me and the players around me. These players act out game after game, ruining it for other people, but when the time comes to punish them they get a warning. Then maybe they'll get a chat restriction. Then maybe a a day ban, and then a week long ban if their behavior continues. Most of the smarter ones don't. They learn to mediate their behavior to an extent that keeps them out of trouble. I've never wanted to quit playing this game because I saw someone with an offensive name, but after hours of dealing with abuse from teammates there have been several occasions where I've had enough, and decided to uninstall.
It's simply too harsh of a punishment. What OP did was offensive sure, but how many people did this actually hurt? What happened in Paris was terrible, but terrible things happen every day. I speak for myself when I say this but one of the way's I deal with tragedy is through humour. “I laugh because I must not cry, that is all, that is all." There should be nothing wrong with this. If players like OP get a permanent ban after a single prior warning, whereas others are allowed to return to the game time after time to ruin it for others before definitive action is taken, then the system is unjust. I'm sure OP has already learned a valuable lesson from all of this and will cease to skirt around the rules of the ToS in the future.
To ignore this plea would be mindless zealotry. Please actually take some time out of your day to read OPs post and mine, and consider if he's really deserving of such a punishment given the circumstance.