I'll post this for anyone who wants to know.
SPOILERS AHEAD
There is a true ending in this game. You have to get the items "A third of umbilical cord" to activate it. These items can be found in these places:
1-The abandoned old workshop
2-Arianna's son (You need to tell her about Oedon Chapel for this to happen).
3-Killing Iosefka (after beating Rom the Vacuous Spider)
4- Beating Wet Nurse Margo.
You only need 3 of these 4 items and you have to consume them before the final boss battle (make sure you reject whatever he offers you). Be prepared though, there is an extra final boss for doing that!
And yeah I didn't figure this out by myself I checked the wiki 
"I've Underestimated the Horse Power from Mario Kart 8, I'll Never Doubt the WiiU's Engine Again"
