Pegasus’ diary claims that losing Cecelia meant that he no longer had the will to paint, however the painting of Shadii and the Duel Monsters cards were all painted after Cecelia died.
After the duel, Pegasus’ deck is left at the arena, but he is then seen with it in the tower. When Yami Bakura is doing his “tarot” reading, the Happy Lover card is at the bottom of his deck yet he draws it without getting to the bottom of the deck. When Yugi goes over to the table, the 3 soul cards are switched in the opposite direction.
The picture of Cecilia is different from the one in THE NIGHT BEFORE.
Correction (for Peggy’s deck): When Yami Bakura came back, he went down to the dueling arena and picked up his cards and THEN went to the tower. This is true because Yami Bakura says “I see in your deck, Pegasus…” But they aren’t going to actually show Yami Bakura picking up the cards, it would waste time. When Yami Bakura flip over the happy lover card, it is upside down, Bakura even notes on that fact. But, when they show Yami Bakura flipping over the Mask of Darkness, the Happy Lover Card is seen Right side up.
In the painting, Cecilia’s skin is tan but, in Pegasus’s memories she has peach colored skin. In the dub, they never tell us what happened to Pegasus.