Order of the scribes get Manifest mind at 6th, this basically seems to last as long as the caster wants it to.
At 14th they get One with the word. "if you take damage while your spell-book's mind is manifested, you can prevent all of that damage to you by using your reaction to dismiss the spectral mind"
The wording seems to me to imply that a player could start the ability in the morning, keep it going all day, take minor damage through the day, major battle in the afternoon, gets smashed by monster, "use my reaction to dismiss manifest mind and regain all HP lost since it was activated this morning, back to 100%! cool, now how many spells do I lose "
I know the cost is pretty high for using this (loosing 3d6 spell levels for 1d6 days), but seems a bit too good, the alternative interpretation i see of just getting the HP for the one attack seems a bit week for a 14th level feature? how do people read this RaW, and how do they play this in practice?
The part you're talking about is a triggered ability, not an ongoing one. If you use your reaction to prevent all of that damage, it only applies to the damage that triggered it.
You generally will want to save this to avoid death, or an enemy's nova strike.
Order of the scribes get Manifest mind at 6th, this basically seems to last as long as the caster wants it to.
At 14th they get One with the word. "if you take damage while your spell-book's mind is manifested, you can prevent all of that damage to you by using your reaction to dismiss the spectral mind"
The wording seems to me to imply that a player could start the ability in the morning, keep it going all day, take minor damage through the day, major battle in the afternoon, gets smashed by monster, "use my reaction to dismiss manifest mind and regain all HP lost since it was activated this morning, back to 100%! cool, now how many spells do I lose "
I know the cost is pretty high for using this (loosing 3d6 spell levels for 1d6 days), but seems a bit too good, the alternative interpretation i see of just getting the HP for the one attack seems a bit week for a 14th level feature? how do people read this RaW, and how do they play this in practice?
The part you're talking about is a triggered ability, not an ongoing one. If you use your reaction to prevent all of that damage, it only applies to the damage that triggered it.
You generally will want to save this to avoid death, or an enemy's nova strike.
As Gruntler said, "taking damage" refers to instances of damage.
Essentially everything in D&D is built around turn-by-turn mechanics, unless explicitly stated otherwise.
While the effect is ongoing, the ability to prevent damage is based on a single damage instance, so if you take damage, you can prevent it.