So far, only three events have been released in Japan. Those three are the Secret Key (in which you gain the ability to turn Rotom into Frost, Heat, Wash, Fan, and Mow Rotom), the Member's Card (in which you gain the ability to capture Darkrai), and Oak's Letter (in which you gain the ability to capture Shaymin). Otherwise, I highly doubt there will be anymore events, for those seem to be the only Pokemon in the Pokemon Diamond, Pearl, and Platinum Version generations that are practically impossible to get without ending up with a hacked version of the Pokemon.
Chat with our AI personalities
you cant catch it anymore
ar codes or Nintendo events
No I don't think so.
Some of the event Pokemon can be found in toys r us on the event dates.
There is no temple of the sea in Pokemon Platinum. In order to get Manaphy in Pokemon Platinum you need to go to Manaphy's special event at any Gamestop (special events are very rare). The temple of the sea isn't in the Sinnoh region.