I will preface this with the note that I absolutely disdain the usage of "toxic" as a modern term, as well as the phrase "toxic behavior", and do not ascribe to the belief that such a thing even is real. Let me elaborate as to what I mean so that my stance is crystal clear. It has been in my experience, consistently at that, a pejorative term used to widely label any form of undesirable behavior without ever specifying the actual type of issue that exists; i.e., "What is the issue?" "Well, that person is being [i]toxic[/i].", resulting in a nebulous and ambiguous quasi-understanding that just something done is wrong without ever denoting if it is actually wrong at all. It is intellectually lazy and we should eschew it for the sake of this circumstance at the very least, for the examination of issues posed, and for the better of us all at large, internet colloquialism and modern parlance or not.

With this established, let us define each particular issue as best we can without carving it into so many that it becomes a mess of technicalities, beginning with the problem of asking the various questions of [i]"Why?"[/i]. Why do people not all get along despite their commonality? The simplest answer, albeit obviously not complete, is that each person will have their own opinion formed from their intellect on down through their experiences. All of their exposure in life, cultural, social, political, familial, and beyond, crystallizes a concept of opinion, which is held to them in their lens as the best possible course of action. This construct may or may not be well defined, refined into a highly functional, multidimensional approach and understanding; typically the only sort of thing built by extensive experience or incredible power of empathy to emulate that of others. Most people realistically lack both and those who tend to be highly intellectual, thus logical, are often calved off by being further divided from that crucial tie that is the aforementioned element of empathy, which is by nature dealing with emotion and thus by nature seldom rational.

Lashing out to strike back is rarely a reasonable response, particularly in a medium as this, because the powers that be often can quell it with nearly no effort. Spitefulness is, by nature, ineffective and only serve to fulfill the wants of the higher mind rather than fulfill its needs, other than a sense of vengeance and what is perceived as "fair play"; the justification of, "If you harm me, I can harm you back." even if the supposed initiator has done nothing wrong. This is amplified by removing the social element of facing consequences, as by famously removing the true interpersonal interactions. At most, without greater interaction, the most personification ever seen by members abroad is an avatar and the content of the words chosen. If one is slothful and puts no effort into the usage of their words or their choice, combined with ambiguity of not having auditory and visual components, it fosters a sense of isolation from that individual and helps regard them to the realm of otherness. 

As such, it becomes very, very easy to be emotionally justified and strike out wrong or right. The stakes are low for reprisal, a counterattack and riposte by the opposition will only seem to further justify yet another response, and they lack any real personhood. For all the concerns of the user with inflamed emotions knows or cares, that other individual is not actually a person, and in our age might realistically - not outside the realm of conceivable possibility - not actually be; see the relegation to anyone who says anything contrary to a narrative, no matter what it is, be regarded as a "bot". This is all a natural outcome of not needing to really answer or suffer for wronging others but having a world that is a one-way mirror peering out, rather than reflecting on to them those things they can see in others that reminds them of themselves. Hence the tremendous amount of exaggeration and hyperbole exhibited on the internet that has, again, increasingly by its pervasiveness alone bled into reality, but still exists with a stark line between the two; rare is it to see people who behave online and offline alike.

Roleplaying, by its nature of taking on other identities, theoretically furthers this. The falling out between persons and the conflict between one another means nothing when another face can be taken and yet another conceptual mask adopted. To ask how they can be stifled is to really ask the impossible functionally because there really is nothing preventing people - other than themselves thus nothing truly at all unless they are of strong character and caliber which most are not - from feeding into this cycle. To stanch such bleeding would require making it more personal and more connected, two elements that have been classically and rightfully advocated against in the internet world. The anonymity and the troubles that come with it are judged superior to being shackled to the retribution of regular expectations.

There is little doubt in mind that any would prefer the alternative, again particularly in an environment about becoming other people and other things in other places and other times, that being divorced from this freedom is positive. Thus, with the beast, its nature so too follows. The good comes with its bad and in the end, the only real metric one can peer into is the quality of person in question. That, fundamentally, determines what creates these behaviors. In another way, what matters is, is the makeup of the individual accessing the internet and how much they may temper themselves.

Of course this begs the question, of what relief is this to those looking into "avoiding or negating toxicity around an RP or another player"? Which I return with this; vet everyone carefully and adeptly. The issue with the so-called toxicity of collectives and persons is that the issues themselves are never addressed, at least not in this day and age. In days gone by, the purpose of blacklisting and banning players who were issues to the community was not only common place, it was expected. There was a rightfully hefty price leveled against those who were frequent and or notorious offenders that seldom had any amount of mercy to them and this was what kept most at bay. "Toxicity" as people call it today is a natural consequence of accepting and allowing everything, hand-waving it on, and allowing it to pool, in place of absolutely abolishing individuals who specifically caused trouble. I might even add before "toxic behavior" became the utterance of choice "drama" was the frequent go-to, so perhaps the matter is more clear now. 

In something as a topic's thread and a roleplay, simply be rid of such people and bar them. It should be made clear that they are an ill fit and that because of their behavior, which was not becoming of the expectation, they should move on. It must be formal, indifferent, and most of all, [i]just.[/i] Unless a player is specifically a known nexus of instability and misbehavior, no one should be closed off to the topic unless the topic is expressly for a listed party of names. It should not matter who they are in [i]any[/i] other circumstance, ever. Any personal matters or issues should be left behind.

So this leads into how these matters can be managed. The first is that, cliques need not always be managed. There never was and should not ever be a mandate that new players should be granted special access to any group for the sake of inclusiveness. Outsiders are just that, outsiders, and need establish a reputation for themselves and find where they belong. This innately takes time, any amount of investiture into a hierarchy does from plants to animals, and that individual is the only one who has any obligation to do so. The community however, should be welcoming of those who do integrate into it, because its long term sustainment requires new lifeblood in the form of outsiders becoming integrated. Pushing prospective newcomers away is an issue of the individuals present but should be self-correcting innately, unless the party in question is woefully incompetent, once they decipher where that individual gravitates to and belongs. However, rejection is a reality of life and not all attempts at integration will succeed. To pretend it is possible is absolute fantasy, as if it were so easy there would never be the "new work place" or "first day of school" experience that nearly all persons have.

Continued, how does one prevent the naturally formed groups from attacking one another? They do not, they [i]moderate[/i] them. Some amount of competition and animosity between factions - those that can be as easily demonstrated as assigning entirely random groups into arbitrary colors, where cultures then form and perceptions of others are created as seen in a number of psychological studies - is innate and inherent. In fact, it is desirable, as competition creates innovation and advancement, and the lack thereof is stagnation and death, at least on the grander scale. As this is such a sweeping phenomena it pervades every element of life, even those so small as say, forum roleplaying. The only effort that should be taken is to invent a code of conduct, an expectation of members socially, a cultural ideal, and a set of rules with good judges on what must be controlled - what must be moderated. Offenders should be punished accordingly and then, by virtue of the cultural ideal, suffer socially as well; this leads back to the idea that in the past, gaining the ire of a community was typically the finality for that individual's stint there, meaning effort would be taken to avoid that and instead appropriately adapt.

In the end, do allow this following proposal to close out if nothing else was clear. The idea of "toxicity" is naive and foolish and goes about removing punishable objective failures by individuals. Instead, all individuals should be weighed and judged accordingly for their failings, both formally and informally. Troublesome sorts, who inflict measurably more harm within the code of conduct and the rules of the community, are the problem and not any one group of persons. Where this spreads and creates a climate issue is when those persons are not removed and they rally together to form bands of similar minds. Each instance of this metaphorical bad blood is contagious, as humans are highly social creatures and maladies of emotion can and do spread from one to another through this mechanism. This subsequently creates closed groups with, typically, unspoken but mutually agreed on general aims and experiences; like breed like. These can often be outright hostile and filled with persecution against their enemies to passive-aggressive out of fear that one step will have them axed. They are suspicious and wary of outsiders even if met on amicable terms. These collective pools of actors will act largely as one entity beyond the scope of any one individual, the usual rallying and bandwagoning seen by friends.

The crux of this issue lies back in the fact that the initial problem individual was never adequately addressed. Whatever they sincerely suffered, if even at all, was insufficient to strike them from their behavioral stupor. In some cases it never will be sufficient by doings of the internet, it is very difficult to influence people through force rather than manipulation that way and the latter is certainly morally dubious and questionably ethical at the least. Thus the only real answer is to strike it down before it begins and create an ethos that operates by example. 

If the community wishes "toxic" behavior to be gone, then it must stop playing into it and let the emotional investiture and energy go. Holding on to it at any amount and allowing it to persist will repeat this problem. So it goes, [@Lord Wraith], the best answer is to not allow it to happen or remain in the first place and ensure malefactors are acted against within the standards of the community.