Casey and Raph have gone looking for an engagement ring for Casey to propose to April when a strange old man gives Casey a mysterious ring. Initially delighted, Casey soon comes to regret putting the ring on April's finger when she starts acting strangely and attacking anything that moves.
This episode provides examples of
- Bad Liar: Hun's not very good at explaining why Raph's still alive when he told his men that he'd personally killed all the Turtles
- Catch a Falling Star: Raph catches April and Casey when Casey removes April's ring, reverting her back to human form a hundred feet up in the air
- Clothes Make the Maniac: The Ring of Yin
- Evil Makes You Monstrous/ Power-Upgrading Deformation: April's demon form. Thankfully it doesn't last
- Letting Her Hair Down: Inversion: If April's hair isn't in her trademark bun the situation generally isn't good. When she turns into a demon it falls loose completely, yet inexplicably returns to its trademark bun when she becomes human again
- Oh, Crap: Hun has one when he sees Raph on the streets. This is revealed to be because he told the Purple Dragons that he'd single-handedly wiped out the Turtles
- One-Winged Angel: April's demon form may apply
- Power Glows: The Ring of Yin
- Real Men Wear Pink: Mikey asks if he can be April's Maid of Honor. At first this just seems like Mikey's signature humor, but in "Wedding Bells and Bytes" its revealed that he actually is her Maid of Honor
- Temporarily a Villain: April, thanks to the Ring of Yin
- That Came Out Wrong: Casey's marriage proposal to April;
- Voice of the Legion: April when she's wearing the Ring of Yin
- With This Ring: I will turn you [April] into a demon.