Roshi dies to 99% of lightning teams round 1 if you put him in the front especially to lightning armor blitz teams, Roshi also dies to a Round 1 high damage combo (basically chases that are high damage like jiraiya lion mane or garras sand coffin), ay 3rd on the other hand does not need to be damaged to scale and he can actually scale to 80% more damage on round 1 if you use samui with him plus he is a ''healer killer'' ninja especially those mabui 1010 teams will disappear real quick once we get cloud treasure. However as good as he is I am still going to skip cloud because I wan't either kurama naruto or Madara from gnw treasure that's why I am saving all my scrolls.

Ay 3rd is an "edo tensei", but again as a f2p i don't think i can afford Nagato unless i'm missing something, i guess gakido or jigokudo would be more attainable.

21k damage with roshi?, maybe against a player with 20k less bp because No matter what if you aren't using atleast 2 healers with your roshi he will die round 1-2. I don't think roshi scales that high if bp difference is similar roshi takes more damage compared to his ninjutsu gains. also if you are talking about ay 3rd then my bad otherwise roshi can't do that much damage maybe combined with his chase but his mystery alone doesn't scale that high against a similar bp opponent.