Wibble Wobble: How do I unlock Hidden Stage 18 in Yo-kai World?

If you have read our instructions on how to unlock Hidden Route 14, then you already know you will be unlocking Bruff on Hidden Route 18. What you didn't know is that this would be much harder to unlock 18 than unlocking Hidden Route 15, which is pretty damn difficult. To unlock Hidden Route 18 you have to defeat McKraken with a Soultimate move. McKraken is a confusing and hard boss to beat, so make sure you have a lot of Y-money so you can spend the 500 to continue.