...is that the creepy guy who keeps saying cryptic things or some other sort of guy.

Probably some other sort of guy, this one isn't wearing a mask.

As Blai approaches, he finally notices the sound of his footsteps. He gives him a terrified look and then breaks into a run.

Okay that's worse. Let's go with a Forbid Action before he's too far away. "Don't move."

He freezes for a moment, blinking in terror.

Blai catches up and claps him on the shoulder with one hand and attempts to confiscate the scythebundle with the other.

Forbid Action only lasts a moment. When the spell wears off he lets go of the bundle, shoves Blai as hard as he can, and attempts to keep running.

Handful of shoulder says no. Who Will Win?

It takes him a few seconds of wriggling, and from the looks of how he was twisting it quite possibly a shoulder injury, but he manages to get free eventually.

Blai does not want this guy running off without explaining himself! "Qualm."

He stumbles and slows but keeps moving away from Blai, now shooting a glance behind his shoulder every couple seconds.

"Explain yourself," says Blai, advancing.

"I, I'm just trying to leave, you never have to see me again—"

"Perhaps your explanation will inspire me to permit this."

"I haven't done anything wrong, it's not a crime to be out at night—"

He speeds up a little.

"If I bring you in on suspicion I think everyone will agree there was suspicion to be had." The Qualm is not working - it's late, he probably doesn't need to hold onto -

"Forced Repentance."

When they brought him into the fold, they told him that he'd have power, that he could be important, that when the demons conquered Golarion it would be safer to side with the conquerors than their food. He'd told himself it wasn't a big deal, that it wasn't like he was a murderer or anything, and — maybe at first it had been true, maybe at first everything he'd been doing really was as little as he liked to pretend. But when he's gotten to the point of tipping off a priest of Deskari about a patrol that would be particularly valuable to ambush, or keeping lookout for a companion trying to release weevils in the granary, does it matter whether his hands were ever personally on the scythe that killed someone? He remembers the look on Karola's face when they told her what happened to her brother, and he'd told himself he wouldn't have been long for this world either way, but even if that were true he could have had another month. It feels like there's some sort of horrible twisted beast crawling in his stomach, trying to corrupt him, but that's not even true, it was still him who made those choices.

He falls to his knees.

"I, I, I've been helping the Deskarans for years, I don't know what you want to know but whatever it is I'll tell you, there's a group of people gathering to the north of the city, I was going to regroup with them — I've been sneaking information for them, helping them take out Kenabres's defenses, telling them where to be if they want to get the jump on a group of crusaders, sabotaging their supplies — I'm so sorry, I know that doesn't matter but I am — two years ago I stole a crate of healing potions and swapped them out for water with a little dye, and they gave me some kind of magic dust to mix in so it'd still look magic — I'm sorry, I know it was wrong, I knew it was wrong then but I told myself it wouldn't matter—"

...this is a really useful spell in a city full of cultists! He's gonna rip off some of the fabric from the scythe covering, while he talks, to tie the guy's hands behind his back so he can march him along to be turned in.

"—and one time I set biting flies on some wizards who were passing through so they wouldn't get their spells back, and it worked really well, so I tried setting them on the barracks, but they just brought in some Gorumite that channeled negative, and another time I made sure no one caught a guy who was trying to let insects into the granary, and I fucked, I don't remember, I haven't been counting, a lot of whores, and I went to counseling with the Iomedaeans and just lied the whole time so I could draw a map of the inside of the temple for one of the priests I was working with — you should just kill me, I don't deserve to live after what I've done—"

"I don't think this spell counts as a trial. The scythe?"

"—it's just a normal scythe, it's not cursed or anything — I helped the guy who gave it to me sneak out of the city when the Inquisition was looking for him—"

The spell breaks. There's — the sensation of a weight that was crushing him, now lifted, except it shouldn't be lifted, he should be feeling just as guilty as he was a moment ago — and they're going to kill him like he deserves, and he'll be sent to the Abyss, and maybe if he hadn't just confessed to half a dozen crimes he could have run off and spent the rest of his life working off what he's done and had a tiny chance of avoiding it, but there's no way that'll happen now, only what right does he even have to be upset about it—

Blai shoulders the scythe and escorts the man to wherever he ought to expect Irabeth to be.

Irabeth is in the Gray Garrison. The guards want to be extra-thorough at this hour, they weren't expecting him and there aren't generally a lot of people showing up so late, but Blai can eventually get permission to enter.

"Select. Report on the prisoner?"

"I was helping the Deskarans, Commander, I—" He breaks off. 

"I was on my way back to Defender's Heart and saw him skulking around in what seemed to be a suspicious manner followed by running away when he noticed me, and I tried my new domain spell and he confessed to a variety of instances of, yes, helping the Deskarans."

He nods. "I, I can tell you what I told him, if it would be helpful—"

He really doesn't want to, that sounds like just about the worst thing on Golarion, but probably the people who are dead because of him didn't want to get killed by Deskarans either.