How do you heal in the Nether?

The devs in the showcase remarked that you might need to have someone go with a full healing build to succeed in the Nether - but like, what build? I haven't tested the options on other subclasses but solar seems to have no reliable way to keep yourself alive.

Healing rifts, healing grenades (even w/speaker's sight), and phoenix dive don't do anything. The Healing ARs seems to work along with the Lumina (edit: healing ARs are also pretty negligible according to others, Lumina still works like it should though) when it comes to helping others, but there's nothing really available to keep the actual healer alive..