Is calling someone "homo" toxic?

Well in what context. While homo means same I assume it's being used as a shortened form of homosexual. If it's not used in a derogatory way it's not toxic. Calling somebody a fa.... bundle of sticks is definitely toxic, homo isn't as bad but if it's used in a negative context then ya, it would be toxic.

I'd say it falls under the toxic subclass if meant in a toxic way.

"No homo" or "You silly Homo Sapiens" are most likely allowed I guess

I mean, in certain context I guess it would slide but just flat out calling people homo will probably arise in offense taken.

Modern society, it's all about relativity, and context plays a part in that. Is it toxic from your perspective? Is it toxic from their perspective?

Is it toxic from Riot's perspective. If it's something even remotely toxic(as they dubbed it, "passive-aggressive") it's toxic. Unless it's fun for everybody else, and no one gets triggered, it's risky.