Final Fantasy VII
Voice Actor: N/A
Dio is the owner of the Gold Saucer, which is a huge entertainment park located in Gaia. He is also well known for sporting a lovely pair of swimming trunks. Due to his immense wealth, he has a huge collection of valuable items which reside in a museum near where the Battle Square is situated - this is also where the Keystone is kept.
Dio originally obtained the Keystone when a weapons collector who lives in a small shack near Gongaga gave it to him. When Cloud goes to the Gold Saucer looking for the Keystone, Dio is very reluctant to part with one of his most prized possessions. However, he agrees to give it to Cloud if he takes part in the Battle Area. Cloud does so and Dio is true to his word - as he gives Cloud the Keystone.
You're Under Arrest
Following reports of a man with a gun-arm killing people near the Battle Arena, Dio makes sure that Barret Wallace and all his associates are locked up in the Corel Desert Prison.
However, when it turns out that Dio arrested the wrong guy (as it was Dyne who commited the crimes), he is very apologetic and gives them his Buggy as a way of saying sorry.
Dio also has a tendancy to refer to Cloud as "Boy", which doesn't particularly go down very well.