Jaredan, a question.

What exactly are the "Rules of Undeath" for Valoran? As seen from the Shadow Isles champs, what are the implications of becoming a super spoopy specter in this universe.

See, this is all I got so far.

As seen from : There exists relics that contain magic that counteracts whatever juju is making sure the undead denizens didn't truly die. We have no idea if those relics always existed or if they were created with this explicit purpose after the isles became all shadowy

As seen from : Undead have a single drive and purpose based upon their life experiences. One single aspect becomes their whole driving force, and all SI champions except Evelynn, who seems to have a wider set of driving forces, even though she has a rather singlemindedness towards her Modus Operandi, and Elise, who isn't undead, thus is irrelevant to the discussion, show this extremely narrow, one-note persona, be it War, Suffering, Death, Fulfilling Quotas, Torment, or most recently, vengeance. Is this a thing for all undead or just 'Higher Undead'?

As seen from : Undead are not limited to Human forms and (possibly) can inhabit items. Is there a significance to, say, Hecarim being half-horse or Mordekaiser being armor instead of spoopy scary skeletons or ghosts? What makes Mordekaiser a special snowflake here?

As mention before: Not all undead are equal. Is there a sort of categorizing system? Do powerful undead like Thresh literally show up overnight or is it a gradual process?

Aside from spoopy SI Shenanigans, can undead be made anywhere in Valoran? If so, can undead that is Kallista tier be made, or does the Shadow Isles have a monopoly on the "Non-shit quality" undead?