KactusPunch
Crown Sage
MarshalSolgriev
SkyeOfStars
princess
Zeroth<Snip>
Blendecs form at Leyline Intersections as malign acts are committed by other species amongst the Fae. It is possible the same is true in Mundus as well, although again it would be tied to acts committed by Fae - Human acts are insufficient for the process. The connection all Fae have with various natural arcane forces (control via true name, glamour, compulsive pacts, etcetera) means that every act made influences the Otherworld (and again, possibly Mundus as well) in a particular fashion. Various natural forces rerout most of this influence through the creation of 'haunted' or 'enchanted' locales and genius loci, or else by generating various natural phenomenon (ball lightning, derechos, will-o-wisps, etcetera). Similarly, the psychological impact upon the victim/s of these malign acts has further influence that stacks with the influence of the perpetrator.
Blendecs specifically are manifestations of intent and willingness to do harm to others. The cognizant nature of the influence itself is responsible for the formation of a sapient being. Implicitly, Blendecs are not the only Fae that form via this process - I would be unsurprised if they are but one of many different kind of Fae that form at Leyline Intersections.
Their very nature is what made the Benign Compact possible. Using the Shards of Caliburn and certain enchantments, it is possible to enable any particular Blendec to become aware of the formation of more of their kind, being wholly aware of the entirety of each being's essence. Enchanting other Fae this way would be impossible, as even if they form the same way they would be formed via different natural processes (hence the need for a Prop-Up 'King' rather than a Lord from another species of Fae) - they would be unable to distinguish the specific forces that culminate in the formation of a Blendec from other natural processes (though it should be noted, a similar compact might enable them to observe the formation of their own kind).
The reason Sathanas was able to suborn the compact was due to the wording. The Courts wanted a stable chain of succession for their puppet kings, so that the Blendecs would never have any 'grace periods' to cause trouble. Borrowing from Human practice, the status of Kingship transfers instantaneously from one person to another, in this case literally. Nobody was around to observe precisely how Sathanas managed to be designated Marduk's heir, but common speculation suggests that he likely compelled the False-King to do so. This is also why the second Compact failed, since Sathanas was by then already technically King of the Blendecs according to the first Benign Compact, which maintained a superior manifestation to the second one by dint of having been formed first. All the second Compact likely did was designate Ashinhil as Heir.
As for the World Tree - I am well aware. Sathanas suffered innumerable trials while they resided near Yggdrasil. The chaotic weft of spacetime there and the resulting anomalies were rather unkind to him during his stay, not to mention any treatment by the world tree itself. I will say Sathanas probably attempted some form of parlay with Yggdrasil, similarly to how the Courts have bargained with it in the past - but without anything like the Shards of Caliburn, any possible bargain was likely unfavorable. The bountiful supply of pitchblende in the area is likely one of the only reasons Sathanas survived.
Modified the history to comply with the absence of the Cauldron.
As for why they hate Mimameith: Reasons.