>>55369891Lol Sinnoh is probably the easiest game to get by with only new Pokemon. There's a reason why you always see the "generic Sinnoh team meme" with Staraptor, Luxray, Roserade, Floatzel, etc. because you get them all early (the first 3 all before Orreburgh and Floatzel after Orreburgh) and because they're pretty strong. I've seen people include Lucario and Garchomp as well because they're also strong but you don't get these until much later (by the time you have six badges) and they're kinda annoying to level up and catch up with your team, especially Lucario.
Even ignoring the six listed above you have access to Kricketot, Buneary, Shellos, Pachirisu, Combee, Burmi, Cherubi, Skorupi and Croagunk all by the time you reach Eterna City. Still relatively early.
This is 15 new Pokemon, not even including the starters. Two and a half full teams of six.
I'm not even being generous to Sinnoh and including crossevos either because then you can also include Murkrow, Misdreavus, Munchlax, Magnemite, Lickitung, Rhyhorn, Togepi, Ralts, Gligar, Magby, Swinub, Elekid, Duskull and Snorunt. All obtainable by Eterna as well. 14 pokemon here. Another two full teams of six. 5 full teams of six if you wanna combine it with the above.