Another tactic if you have Set/Return to Portal spells for at least 2 characters (other than Vi), is to a) Set a portal with the first character at the entrance of Bayjin or Away Camp just before Vi or RFS-81 refuse to go further.
b) Return to Arnika either by walking or portal, go to He'Li's, drop off Vi and RFS-81 (Vi will stay at He'Li's and RFS-81 will stay wherever he is dropped). Set a second portal (second character) at He'Li's.
c) Portal back to the Bayjin or Away Camp entrance, walk thru the entrance, and set a new portal with the first character (be sure you don't over-write the portal to Arnika).
d) Portal back to Arnika using the second character's spell, go to He'Li's and pick up both Vi and RFS-81.
e) Portal back to Bayjin or Away Camp and both Vi and RFS81 will stay there. Vi will complain constantly in Bayjin or the Away Camp or any of the other Rapax locations, RFS-81 complains constantly in the Away Camp, and there is supposedly some impact on skill levels, but I couldn't detect it. Both Vi and RFS-81 gained levels in both locations despite all their grumbling. Be sure you have picked up an extra set of scuba gear for Bayjin if your portal is set underwater.
This strategy is particularly useful in the final end-game, as Ascension seems to be one nearly constant battle after another, and there are NO places to camp without being interrupted. Transporting in and out saves the day, literally.
Hope this helps.......