Yes, it is possible to complete the Pokedex in Pokemon Storm Silver. The Pokedex in Pokemon Storm Silver is the same as the one in the original Pokemon Soul Silver game, and includes a total of 493 Pokemon from the first four generations of the Pokemon games. In order to complete the Pokedex, you will need to capture, trade, and evolve all 493 Pokemon. This can be a challenging and time-consuming task, as some Pokemon are only available through special events or by trading with other players. It is also worth noting that some Pokemon can only be obtained through cheating or hacking, which may not be considered a legitimate way to complete the Pokedex by some players. However, for those who are willing to put in the time and effort, completing the Pokedex in Pokemon Storm Silver is a rewarding accomplishment.