I'll leave the technical parts of this to the designers. Stuff like how much pips it costs, what it's called, and so on.
The idea behind this astral is that while it is running, your blades are immune to being broken EXCEPT by the spell you cast that uses them. It would be good if it also boosted your pierce. As a side effect, it might drop your damage or your critical, or make you take extra damage, or drop your accuracy.
Because of this, it should be a high level spell only available from the arcanum scholars.
