I have a diffrent view on thresh's lore and quotes.
pros-----
He doesn't apear to me as the sunday morning cartoon vilian.
more or less he seems like a real life serial killer.
He is sarcasticly mad with his taunt and his moveing lines.
He stalks whoever he is interested in for weecks before he takes them to his prison in the shadow isles.
He has a prefered method of torture. chains.
his kit makes him realy thrive on that pain his team causes.
UNLIMITED TURTURE in his prison.
meager pondering----
-how old is thresh?
-the shadow isles? are they 3 isles, 4 , 5 20? how big are they, seriuosly all these champions are coming from there, and so many own aton of land. Karth has a whole kingdom, elise atleast has two or three caves, thresh owns a large prison to acomadate everyone he's taken there over his life time hecarim roams so there must be alot of forest, eve needs some people to drain from so there must be a beach of a town.
-how are minions dropping souls? they are AI units, in their lore. Is the instatue of war putting peoples sould inside the minions, if so does the instiutute of war have some secret underground darkside with people like fiddle, and etc.
-his involvement in the shadow isles, i think is parralel to karthus's where both simply go to the shadow isles to use it's sacred power of life after death. Where before they where normal people.
- his team fight thing, where he is played as support, just seems to me he likes the fear and suffering, and he is indifferant to if he kills them or not, long as he gets the soul.
-tldr-
minions are AI units, how are they droping souls?
he likes suffering
he is mad
he is sarcastic
he uses chains, not blades.
I think he's more likely to know karthus then hec, eve, or elise since they both are large shadow isles land owners.
cons--
nothing about shadow isles.