Lb7 details that i might have missed?

So...why did Daybit help ritsuka? Why did he give him those resources to cross the underworld?

I tried racking my head around it but i couldnt find a proper in-story reason. Ritsuka was at no point usefull to daybit in his quest to reawaken ORT. That is unless he used chaldea for Izcalli since he needed more training to become Tezcatlipoca. But then again Daybit commited suicide for the reawakening, so Izcalli was lowkey useless. At the end of the day Daybit would have died to ORT anyway so... He could have sacrificed himself from the begining? Also what was the point of stealing the sun again?

In this scenario the one thing i can think of is that since Daybit has been shown to be a genius with incredible clairvoiance, he used the whole lostbelt as a means to test and train ritsuka to defeat Chaldeas, and possibly to indirectly destroy U-Olga to get the biggest obstacle out of Novum Chaldea's way