When Tiamat enters the battlefield, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle
A deck contains the same number of cards
However, if they dont deal with it, the game is pretty much over
Some people use Pecharunt to add exactly the two cards they want, while others use Professor's Research to draw 7 cards, pulling both of those desired cards while aiming for further high-rolls with the remaining 5 cards, and some people use Fezandipiti ex's Flip the Script to draw both of the cards they want
The fireworks pattern, in this Pokemon trainers opinion, looks stupendous on Water-type cards and especially good when paired with the best Kanto starter (dont @ me)