Positive Energy
The pole of living force: creation without form, too much of it to stand in for long.
Positive Energy is not a place so much as a condition: living force without form, and so much of it that nothing unprotected stays coherent there for long. It is the source the four elements draw on and the pole every quasi-elemental plane on the bright side is mixed from.
The Martyr holds it, which the faithful of Idir find obvious. Her portfolio is endurance, understanding and perseverance; her shrines are old ruins rather than temples. The pantheon has never set down why a goddess known for outlasting things sits at the source of living force.
Souls come this way. They are meant to join the Inner Planes at death and become, over centuries, part of what claimed them.