So this basically confirms that this will be the definitive time loop because Albus will disappear if he tries to loop it again. In other words, he needs to use this loop to find a true way to save Fiona... Well I'm kind of glad since it seems this loop is being taken a lot more seriously with the members gaining fragments of the past timelines' memories. But that also means that the consequences of the time loop are actually affecting them as the timelines memories converge... maybe that's why the god's messenger came to send the warning.
Also very interesting to know that it was the messenger who gave the power to Albus. Honestly unexpected but not surprising at all.
And another note to add, Albus met Fiona first as a Demon King vessel before meeting Fiona herself as an individual right in the next timeline.. To be honest, it seems he took an interest in her so it's kind of cute to see.