Timer didn't exist in Ryuga timeline, the reason is different Soul Metal used.
In Kouga-verse, Soul Metal is made through ritual by Makai Priest, trying to replicate Horrors body properties on processed metals.
In Ryuga-verse, Soul Metal obtained by harvesting it from trees that grew from scattered Zedom body parts, said tree branch can also be processed to make dagger Tousei used to produce Madou Horror.
About Ryuga current development into mentor, looking back ...
Yami established Ryuga timeline will be dealing with byproduct of Zedom body parts as Zedom can be resurrected as long there's any of it single body parts left, not to mention civilian like Tousei can obtain access to it. Gold Storm effectively ditch Zedom, introduced Ago and Jinga, conflict escalated to prevent them obtained access to world-ending ancient rituals.
We can always go back to Zedom ... but, mentor is the way to save budget, yes.
