Spamming all 3 each day to buff her life as a longterm stopgap won't work?
Putting aside how it works in-game, command seals in the Fate series are very finite, one master can only have 3 command seals, and they do not regenerate over time. Once a master uses all 3, s/he immediately loses control of their servant.
Wonder why they can't use command spells to give mashu a normal life span?
A Command Spell is an Absolute Order that the Servant must follow, not an Omnipotent Wish-granting Machine. If the Servant can't physically do it then jack all happens and the Spell is wasted. Not to mention that they're a limited precious resource that can work miracles if the order is super precise, no sane master would waste them on something as trivial as keeping their Servant topped up on mana. That's what the muggles are for.
Putting aside how it works in-game, command seals in the Fate series are very finite, one master can only have 3 command seals, and they do not regenerate over time. Once a master uses all 3, s/he immediately loses control of their servant.
That is assuming the command spells in Grand Order is running under the same rule of course. I don't think they have addressed how command spells work in FGO yet.
