One Epic Train Chase/Opening the Portal to Tartarus and free Bill Cipher and the Nightmare Family

Here is how.

In the tunnel,.

????: Oh slow down,.

????:

????: Oh,.

?????: Relax, ????. At least, this crazy trip will be behind us.

Suddenly, the mixed together Skeleton Guards appeared on.

Skeleton Guards (Mixed Together): Grrr!!

Pedro: BEHIND US!

???:

Princess Yuna: No, look behind us!

Skeleton Guards (Mixed Together): You can't leave.

????: FASTER!

Train: