Looks harmless enough.

Well, looks being the key word here.

He crosses through the portal anyway and takes flight. Any sign of people or anything obviously unusual?

There are birds, downed in the mud and struggling. No people.

Poor birds... If there is no people he lands and inspects a bird. Anything unusual about it? Signs of magic?

"Are you okay?" He asks pushing his translation to work in case it's a person.

He carefully fishes it out of the mud and summons some rain to wash the mud away.

There are no people visible. The birds are unusually colored and not of Earth species but not otherwise remarkable. They don't respond to the telepathy.

Does it at least responds nicely to being cleaned? Felix pets it absently assuming it doesn't turn aggressive.

"HELLO?" Felix shouts at the top of his lungs. "I WANT TO HELP!"

Some of the birds try to fly away. They fail. 

Well, Felix is not sure what this is supposed to represent, but he is sure it's a metaphor for something depressing. He takes flight and keeps shouting, calling in for more rain to see if it helps the birds situation. And keeping an eye out for the dreamshaper. "I know this feels like a dream!" Felix says. "But you're under a magical effect! I can help! You need to find a portal and leave!" and variations with similar meanings. Sometimes he is quiet, waiting for a response. Maybe the dreamshaper is invisible, or is a bird or something even weirder.

More rain seems to make the birds' situation worse, if anything. 

Eventually one of the birds thrashes particularly when he talks about finding a portal and leaving.

What if Felix tries the opposite and instead tries to dry them up? (This won't dehydrate the birds.)

He notices the bird and lands carefully near them. "Hello? Can you understand me? Gawk twice for yes."

He picks up the bird and tries to clean it.

Bird seems utterly terrified by this but goes very still.

He is very gentle about the cleaning.

"I am not going to hurt you. Can you understand me?"

Such a still still bird.

"You're so still that I can only assume you can understand me."

Felix dries up a patch of muddy ground and gentle deposits the bird there.

"I want to help."

Bird doesn't move at all.

Felix tilts his head. "I know you're red."

Bird maybe curls up slightly.

"The reason why I am here is that if I don't take you to a portal you won't wake up. I am going to make my best to help you with that. But another problem is that the thing that caused this is likely near your sleeping body. It's a gray quartz crystal and I need to keep it safe. Many more lives might be engendered otherwise. Many, many, many more."

Tiny shivering bird.

Poor thing. Even if it isn't the dreamshaper.

Felix takes it to the portal and puts the bird through. If it is the dreamshaper then it will vanish.

Yup.

Felix sighs in relief. He walks through himself and then goes to the red neighborhood.

When he lands people flee again.

"I mean no harm! Please! I need help and it's very important!"

Nope.

God, may he have not fucked up.

He tries knocking at a door where the dreamshaper possibly is.