Internal Vis Virtue

Pg 94, it's a lab activity taht takes a day and can be done while the magus is doing other lab work.

Interesting, I had never considered being able to use this effect to "drain" the vis out of a living creature. I'm not sure that was the intent, however the rules don't seem to prohibit it. Thanks for the edification.

If you drain the Vis from a creature with a Might Score ,
does it replenish though?

A creature with a Might Score doesn't contain Vis while it is alive. It has a Might Score instead. Once it is dead, the power coalesces into Vis.

Ahh, interesting. So someone with this virtue would be something totally new and thus needs new rules to govern it (or pick one that exists).

Personally, I'd give the character a set limit beyond which the vis doesn't accumulate, and no way to extract it. Use it or lose it. For example, 1 pawn/season with a limit of 4 pawns would allow him to pull off one ritual per year without vis and nothing more.

In any case, such a character would be of great interest to research-oriented Bonisagi ("You MUST let me study you...")