I usually pick Khrone because I find him the most relatable with nurgle coming a close second for me and are more comfortable to rp for it. Not dissing the other two, I like all four and went a word bearer last time I was apart of a chaos rp (wanted to go human this time though.) But with Tzeentch, there's the whole maze of lies and fates thing attached to it and I'm just horrible at extreme planning and forethought (even though magically nuking someone is fun) And with slaanesh, there's always kind of a big stigma attached to it because of how people usually perceive the Dark prince and then trying to find something your character finds pleasure in that can stay relevant to the rp (at least for me, never gave it a serious chance before). Don't for get the saying "The road to hell is paved with good intentions." Looking forward to your character then.