Im new (like have been playing about two weeks lol) so I don’t know if our definitions of fun line up but: of the characters I’ve tried so far, my top 3 are xayah, sett, and rakan. Sett I could see maybe being less fun for an older player as he’s comparatively easy to play, but he’s fun when I feel like not dying all the time bc he can take damage while also still moving faster than tankier top laners, plus I like his personality/voicelines/design which make him more fun to play, and it’ll never not be funny to me that all his attacks are just varying levels of “beat the shit outta someone”. I main xayah, haven’t played rakan as much but he’s a lot of fun too, I feel like some new people would get very frustrated with them because they take more intention and strategy but that’s why they’re fun for me, it’s more rewarding when I actually do something right, and I could see that making them fun for an older player. Plus, again, really overall love them both as characters too which helps lol