Take it to the museum in Nacrene City
Do you mean Archen? You can revive it in the museum from a fossil you get from a man in the Relic Castle. You can chose between this fossil and another one.
you probably forgot to go to the dragon helix tower, after that the ancient castle and after that the shippou city museum.
Dock is located at the Shipyard in Slateport City. You must talk to him in order for the Team Aqua/Magma grunts to move, allowing you access into the Oceanic Museum.
You don't get Deoxys from anyone in the mining museum You have to trade it from Diamond/Pearl, or migrate it from Ruby/sapphire/emerald if you went to any of the events.
It's in Lilycove City.
If your Pokemon scores five hearts or more in a contest, you'll get a portrait of it that will go to the Lilycove Museum.
He's in the museum.
While in Lilycove City, you can find Captain Stern in that museum place where Team Magma/Aqua are standing by. I forgot how to get rid of them, but once you do, you can find Captain Stern in that museum place I mentioned.
You have to win the master rank contest at lillycove city
The art muesum is located at Lilycove City, at the top left.
Win inthe Master Class Contest then talk to the guy in lilycove museum :-)
You must win a Master Rank Contest by a certain number of points above the others, then the artist will paint your Pokemon and put it in the Lilycove Museum.
it is in sootopolis city but under water in satapolis city Museum
Take it to the museum in Nacrene City
In the Lilycove City, if 5 paintings of your Pokemon who won the contest are exhibited to the Art Gallery's second floor, the Curator will give you a Statue of a Legendary Pokemon... But about the Art Dealer outside, I still don't know what to do with him...
Glass ornament is received in the Arts Museum at Lilycove City. To get it, you must win each type of master rank contest (cool, cute, smart, tough, beauty) and have your Pokemon drawn. Then, go to the museum which is right beside the department store, go up the stairs and talk to the people. One of the people there will thank you (you need to talk to that person first though) and give you the ornament.