It resides predominantly in the Kanto region, known for its vast underground tunnels and cave systems where Digletts are found in abundance, such as the Diglett's Cave
Especially in the early series of the anime, its fair to say that the TV series had a somewhat loose definition of the rules
(In the dub, Yusaku specifies that he is looking for Ai.) This shows how close the two have become over the series and solidifying themselves as close friends
Its Special Summon condition, "by Tributing a WATER monster with 0 Attack and 10 Stars", corresponds to its original form, "Metal Reflect Slime"
When you shuffle cards you should always follow up with a cut
This meant that a player could use Lysandre Trump Card once and after a while, use VS Seeker to use it again, entering thus into situation with infinite resources