ElMonoEstupendo

Correct! Sometimes (although not canonically) called Asterisk.

Not Shallan. Not Pattern. Not Szeth's Highspren. Not Allomancer Jak. Not Nazh. Not Hoid. None of Sja-Anat's Enlightened spren. Not Waxillium. Not Ais. Not Lightsong. This character investigates people. This character's real name is unknown. This character has been called a stand-in. This character is quite cutting at times. This character helped feed the hungry. Bonus Clue: This character was (probably) made on a different world than where we see it.

Not Pattern. Not Szeth's Highspren. Not Allomancer Jak. Not Nazh. Not Hoid. None of Sja-Anat's Enlightened spren. Not Waxillium. Not Ais. Not Lightsong. This character investigates people. This character's real name is unknown. This character has been called a stand-in. This character is quite cutting at times. This character helped feed the hungry.

Not Shallan. Not Kelsier. Not Vathi. Not Spensa. Not Alcatraz. This character almost worked for a villain (indirectly). Oh my, it actually almost happened twice for the same villain.

Not Allomancer Jak. Not Nazh. Not Hoid. None of Sja-Anat's Enlightened spren. Not Waxillium. Not Ais. Not Lightsong. This character investigates people. This character's real name is unknown. This character has been called a stand-in. This character is quite cutting at times.

Alright, I'll go again! This character almost worked for a villain.

Not Hoid. None of Sja-Anat's Enlightened spren. Not Waxillium. Not Ais. Not Lightsong. This character investigates people. This character's real name is unknown. This character has been called a stand-in.

Not Waxillium. Not Ais. Not Lightsong. This character investigates people. This character's real name is unknown.

Nice! This character investigates people.

Count Ahan, the swine.

No more guesses? The answer was Sandra, who taught Stephen Leeds how to harness and cope with his aspects. The turn is up for grabs - whoever wants to can go next.

Stormfather.

Not Preservation. Not Ruin. Not Alcatraz Smedry the First. Not Moash. Not Anthony Davis. Not Shai. Not Nergaoul. This character is imprisoned. This character has a lot in common with a protagonist. This character lost a superpower. This character disappeared without a trace. This character can't make up their mind any more. Bonus Clue: This character used to make their own company.

Not Alcatraz Smedry the First. Not Moash. Not Anthony Davis. Not Shai. Not Nergaoul. This character is imprisoned. This character has a lot in common with a protagonist. This character lost a superpower. This character disappeared without a trace. This character can't make up their mind any more.

Correct! His name is "Winds" and it's mentioned precisely once. I thought it was a curse like "storms", at first.

Not Moash. Not Anthony Davis. Not Shai. Not Nergaoul. This character is imprisoned. This character has a lot in common with a protagonist. This character lost a superpower. This character disappeared without a trace.

Not Thaidakar. Not Kalak. Not Vathi. Not the Lord Ruler. Not Silence. Not Beldre. This character stays safe in a dangerous place. This character indirectly threatens a whole world. This character works for what seems to be a powerful organisation. This character opens the path to progress, but more than they were expecting.

Not Anthony Davis. Not Shai. Not Nergaoul. This character is imprisoned. This character has a lot in common with a protagonist. This character lost a superpower.

Not Shai. Not Nergaoul. This character is imprisoned. This character has a lot in common with a protagonist.

Not Kalak. Not Vathi. Not the Lord Ruler. Not Silence. Not Beldre. This character stays safe in a dangerous place. This character indirectly threatens a whole world. This character works for what seems to be a powerful organisation.

Not the Lord Ruler. Then you're in luck! Not Silence. Not Beldre. This character stays safe in a dangerous place. This character indirectly threatens a whole world.

Excellent choice! This character is imprisoned.

Soonie! This character stays safe in a dangerous place.

Obliteration.

Mmm... Rashek?