If you wish to take Vi and any others, eg, Madras into Rappax rift, you merely have to transport there. You can do this from T'rang teleporter, which you enter from Marten's Bluff. Don't forget your red and white wires.

The downside is that they will complain the hours away, and get the bonus of a permanent Hex spell on them (-20 on all stats) while they are there. There are other ways to get them there as well, but I just take RSF-81 - there is only one place he won't go, and that takes little time at all to complete.