The Portal Domain doesn't have Teleport. To me that feels somewhat off and I feel like it'd be a neat twist without being an absolute game breaker.
If memory serve there's a cleric domain that gives Undeath to Death at like IV and other strong spells. Harm received by some domains and likewise at Circle V
If it's not too hard I'd suggest giving the Portal Domain the spell Teleport at Circle IV or Circle V.
This would be cool!