Is it risky to buy a domain with a trademark name?

Honestly, I think it really depends on your intentions. If you're using it in good faith and not trying to mislead anyone, you may be alright. Just be cautious about any trademark complaints. For reference, my school owns the domain luc.edu, but unrelated developers are running luc.io and luc.net without issues, so having a legitimate purpose for the domain does help.

Absolutely, it's situational. In your case, it appears you might be infringing on a trademark that's already registered, which is usually seen as bad faith. You might end up in hot water if they decide to challenge your use of it.

Yes, it's definitely a risk! You should look into the specifics of the trademark laws and how they might apply to your situation. Typically, they'll have guidelines on what could be considered infringement. For instance, I was interested in a domain that shares my last name, but it turns out it's also linked to a college with trademark restrictions against using that name for educational content. Since my use would just be for a personal portfolio, I believe I can justify my claim very well when I have the funds to buy it. In your case, if you can present a valid reason for wanting the '2xko' domain and make sure you don’t infringe on what they protect, you might be okay. Just remember to throw in a disclaimer stating that you're not affiliated with Riot Games on your site!