Mafia 99. The tragedy of the city of Ve-He.

If one of the sweethearts is blocked, but not isolated or in jail, will the Night Duel proceed?

How is evidence provided for mass murders? Is there one piece of evidence for each victim?

It will not proceed.
Yes.

What if all the others are in jail? Does that count as "only one remains"?

Yes. But if they leave, he loses the ability to kill.

What if all the others are in jail? Does that count as "only one remains" in this case?

No.

Added 1 hour ago
Patch 1.0:

1. After Zesma's death, the curse is lifted from Ryashu.
2. Toregis's deadly raid can be used once every three nights.
3. Oben's Dance of Death becomes an ultimate ability that ignores external and natural defenses and kills the defender.
4. I am removing murders where the player's role is not revealed.
5. After Oben's death, Ryashu loses the ability to use Hatred of the Unknown, but does not die.
6. Kost loses the ability to compare stats after being resurrected by Torsoh.
7. The faceless murder of Igelax will occur once every three nights. Igelax will receive a defense that prevents the murderer from performing Night Duels for one night.
8. I will add a block and status change to Zesma, which she will receive after Raven's execution.
9. I will add the ability to silence Toregis.
10. Ryashu will be able to use Hatred of the Unknown together with the murder.
11. Ryashu will ignore blocks and isolation.

This is still not final. Changes are possible.