Here are some demons! Three of them, eight feet tall and emaciated, with ribcages that are literally hollow—the bones stick out like teeth. Their proportions are just slightly off from a human's, and their hands and feet sport wicked claws. 

They're on her side of the barrier, unfortunately, being urged towards her from three different directions by frantic smoke clouds. 

(Meanwhile, her temporary cork shudders as something throws itself very hard at the opposite side.)

Of course there are demons.  What happens if she tries healing them?  (Obviously also healing the wraiths in the process.)  And if that doesn't work...

A construct lasso ought to hold them.  Unless they're Some Bullshit.

The wraiths can be healed. The demons can't, but they have no defence against construct lassos. 

If she lets the demons get within 20 feet of her, though, they're going to reach out and claw at her soul with something that tastes foul. 

Hell no, she's not letting herself get pinned against the ground when there's still enemies out there.  They can dangle while she hovers in the sky.

Though if they're smart enough to try and lull her into a sense of false security, it's possible she'll get close enough, investigating them, for them to do that.

And when they do...

They find out exactly why Diana's soul is so tightly woven, chains upon chains upon chains, as they jostle something important-looking and in instinctual response her rage sears down the connection between them to burn the demons that thought they could mar her soul, from existence.  She will not be diverted from her path!  You will not make her throw compassion away!  She will never be something like you!

The demons are more substantial and harder to burn away than any monster she's met so far in this world, but if she puts enough effort into it, she can burn them out of existence if she wants to. They screech and wail, but can't wriggle out of their bindings.

There's intelligence there, if she looks, but their minds are very different to human minds. They're architectured around a deep hunger for the souls of the living, and all other thoughts and desires warp around that hunger like cosmic dust around a black hole. 

...What, she wants to know, the actual fuck, is even responsible for these things?  They are - no longer close enough to hurt her, and she's healing, and thank goodness she cares enough about herself that way - but - 

(Her shield is wavering, Diana's focus drawn askew -)

Whatever force created these things, these thinking beings, and filled them with only empty, unfillable hunger for souls, is going to have a very pissed off Indigo Lantern give them a talking-to.

In the background, the shield collapses into a massive, flaring sun, a signal pyre of her rage - and her compassion, too.  All who see it know two things:

This cannot continue as it is -

- and -

to leave unknown and uncountable infinities of tortured souls in bondage to the whims of the desire for death they've had forced upon them is anathema to her, and one she will redress with all due haste.

And if whatever god it is that made these creatures, the ones she has bound in chains much like her own in lieu of better options, has a problem with her light reaching out to souls trapped in their darkness -

They're welcome to come make an issue of it in person.