Triggering the statue mechanism only opens the door to the church, if you haven't obtained the Magic Key from Aricen, the event of Arthur's assassination will not take place.
go to the forest near your house and straight to the sun you'll get to Grailwood village (after saving Kay you'll have a letter so you can get it), talk wif sir Percival and do his quest to get Ban's key, go back to your house and open the basement to get the Excalibur husk, wif it in your inventory, go to the purple/violet magic barrier near your house, the barrier will be gone so you can get to the Ruins, he stands in front of the castle ruins, he's a satyr :D