Spell Binding
A Minor Hermetic Virtue presented in TMRE 27, Spell Binding allows magi to bind spirits into containers, forcing them to sustain a spell indefinitely.
Use of this virtue requires the casting of the Ritual Spell Sustain a Spell of (Form), so that raw vis is still required to create permanent-duration effects. Unlike a magical item, however, the bound spell need not emanate from the physical container, although the two are mystically linked.