One unique aspect of vortices is that more than one person can help create
them. In particular, up to two additional 'casters' may perform supporting
roles, hopefully allowing the vortex to stabilize more quickly. Naturally, the
faster the process is done, the less stressful it is for all concerned.
This skill is automatically in effect when supporting a vortex; be aware
however that you will be in direct contact with the magical energies involved,
and hence will be drained more than regular bystanders.