CS is harder to master mechanically. Valorant is strat wise harder. Niko, being one of the best cs players, this mf would be in discussion to be the best aimer in valorant if he's already in discussion in the cs scene.
Ofc he switches he has to learn. Everybody does. But being one of the best aimers in CS he would definitely have it easier than other people. Niko would prolly shit on Demon1, Yay, Aspas, and Tenz if we're talking about head clicking