is all players on karjala cup gonna be u20 for russia or some players older?
Karjala Cup will feature most U20 candidates for the WJC with an addition of a fair number of young players who are not U20 eligible anymore though. Nikishin and Chistyakov on D(one year overage for the WJC). Bashkirov, Safonov(1 year), Voronkov (2 years), Galimov (3 years), Tertyshniy(4 years) for forwards. So it will technically be a U24 team while most players will be U20.
They spread the tealent a bit between the Karjala Cup team and the team for this tournament. Miroshnichenko and Yurov will lead the way at 4 Nations alongside gaolie candidates to back up for Askarov at WJC and still quite a few strong candidates to make the WJC team in Zlodeyev, Trineev, Kisakov, Poltapov, Ivantsov, Lazutin. All forwards though. The D for this tournament will bare feature someone who will make the WJC roster.
Russia's forwards selection for the WJC this year will be a blood bath. So many talented underagers who have already secured the spots. The team for the 4 Nations Tournament won't be pushovers or a clear cut Russia2. It has a fair amount of talent upfront. And that said there are stlill a couple of forwards who won't play in both tournament, but I would consider WJC candidates. That's how crowded it is.