I had been wonder trading and was asked to link trade and was traded an egg. I didn't think much at first until I noticed the Pokerus, and that the name displayed Japanese characters instead of being called 'egg'. The summary also says "It looks as though this egg will take a long time to hatch." Bad egg or not? Afraid my game may end up breaking if it happens to be one.
Even if this was a Bad Egg, it's unlikely your game would be permanently misconfigured. However, it's likely this Egg is legitimate: the Wynaut and Togepi Eggs from ORAS display this message and are the only Eggs that can legally do so.
Egg cycle (Bulbapedia)