The only thing I'm aware that Oasis can change is the prices on items/ninjas. For example, the German server has certain items such as lucky dice at 50 coupons while we have it at 20. In terms of game content, it is up to Oasis if they want to add their own events in Hot Topics. Even Taiwan added their own events in Hot Topics yet still have the same content as China (they currently have the bond system). It seems like game content like ninjas and system features (ultimate training, summon cultivation) on all servers follow China. In terms of nerfs and buffs, you have to figure out whether previous servers did it as well (for example: did China nerf tobi in between 1.0 and 2.0?) or is this the first time in all servers.