@mage_goo Mana capacity is fixed when one is born. Most people except real royalty have only average amount of magic like Zenjirou. Royalty in the Southern Continent can use unique Bloodline Magic as well as having larger than average mana. The way the magic works is that when one has two bloodlines, they would need to be born with at least twice the amount of mana to pull it off. It wasn't really explained why though. In terms of Mana, Aura can use her Teleportation spells a few times a day. While Zenjirou can only use it once or twice a day.
Another explanation given in the novel was that people with large amount of mana find it is very difficult to control small spells. While they can cast large scale magic, they have trouble casting small precised spells properly.
And "Bestowal" can only store spells into tools, not Mana. For example, Francesco can bestow Fire Magic into the wedding rings, but one requires their own mana to use it. The magic tool in question is done with Aura as a collaborator since it is a tool she ordered from Francesco. Aura has the unique "Space Time Magic", and one of the spells unique to her bloodline is "Future Compensation", so she worked with Francesco to "Bestow" her unique spell into the magic tool.
Francesco can't make the "Future Compensation" tool without Aura. At best he can make a "Healing" magic tool himself since he has both Bloodline magic to do so, without requiring the Jilbell Royalty to participate.