Her first card, Tamiyo, the Moon Sage, was a key part of several control and counter-burn decks of the time, and was arguably the most successful
Extra Deck 15 Beast-Eyes Pendulum Dragon X EARTH Level 8 [ Dragon / FusionEffect ] ATK 3000 DEF 2000 1 DARK Dragon-Type monster + 1 Beast-Type monster Must be either Fusion Summoned, or Special Summoned by Tributing the above cards you control (in which case you do not use "Polymerization"), and cannot be Special Summoned by other ways
However, there are forces working against the investigators, represented by the Agenda deck and encounter deck
Time Stands Still: Arcana Force XXI - The World's "heads" effect is in reference to the fact that this monster is based on the Lovecraft deity of all time and space, Yog-Sothoth
If heads, a beam will shoot at the opponent, dealing 900 damage