There's several flaws in your duel with Zuzu and Y/N in you're "Arc-V: Family Matters" story., because Y/N could've OTK'd her,
1. Performapal Sword Fish is using it's O/TCG effect instead of anime, and it's second effect changed from triggered by normal/special summoning to auto. And you're not using it correctly. you have the affected monsters only losing ATK, when it affects both ATK and DEF simultaneously. Mozarta should be down to 800/1400 like Canon.
2. Whip Snake's effect is now a Quick Effect, when it should only be activated during either Main Phase once. per turn.
3. Melodious Illusion only works in response to Trap(and Spell in O/TCG version) effects, not against monster effects, and also in anime, only activates during the player's own battle phase, in response to an opponents trap activation. Even if it did work on monster effects and have its O/TCG effect, Zuzu could've activated it during the Main phase and returned Mozarta to her original ATK and DEF before the battle began, since Timegazer and Stargazer's pendulum effect only works during battle with pendulum monsters, and prevent the possible OTK.
4. Also regarding Stargazer and Timegazer, you're using O/TCG and not Anime pendulum/monster effects. Please choose one or the other and not go back and forth between cards.
5. Zuzu has Soprano, who supports Fusion Summoning, which Zuzu had not learned until after Sora showed up, so she would likely not have or use any Fusion support cards.