The Antagonists of My Inner Life are surprisingly rather few and far between and most of them are conniving, one-note and pun-cracking, which sort of lessens their threatening nature.
Dark Link[]
Dark Link is our first real antagonist (not including Mido, since his stance is ambiguous) to make a physical appearance in the story. Ruto discovers and is accosted by him at the Water Temple and Link returns to defeat him, horrified that he didn't the first time around. Dark Link takes Jenna and Link prisoner and frequently leaves them unattended for reasons that are never specifically given. Dark Link's motives and intentions for doing any of this are never explained, though considering the encounter with him was the one in which Jenna discovered her elemental powers, it is probably a safe conclusion that this was his entire purpose from the start.
"Gannon"dorf/"Gannon"[]
Though we never actually see or hear anything from "Gannondorf" (presumably based off of Ganondorf from the canon) we are told repeatedly that he is still very relevant and very much a threat. As far as we know, however, he is still securely locked in the Sacred Realm.
Dark Lord Ariakas[]
The Dark Lord Ariakas is the leader of the Draconians and Dark Knights, an apparent race of people that conquer and domesticate dragons. They are apparently evil because they are "hell bent on total annihilation of all who oppose them" (perhaps another way of saying they are protective of themselves and their culture and will fight anyone who tries to interfere with that or compromise their safety). Ariakas is evil simply because he originated from the Shadow Realm, which automatically makes anyone evil by default.
Despite all of the mentions he gets in the story, we don't actually ever come face-to-face with him. It can probably be assumed LQ planned to have him appear and be single-handedly defeated by Jenna.
There is a rather compelling fan theory that Ariakas might be Link Jr. from the future, out to get revenge on his parents, though considering the amount of depth LQ usually displays in her writings of this time, this was most assuredly not an intentional suggestion on her part.
Mido[]
Despite a rather flattering description in his initial introduction as a "dear friend of Saria and Link", this is rather quickly contradicted when he so boldly and presumptuously asks for an explanation as to why two non-Kokiris should receive Kokiri fairies. When Saria snaps at him for having the gall to even wonder such a thing out loud, Mido grumbles off and Saria is forced to apologize for his decidedly appalling behavior.
Mido is a rather good example of a character turned into an antagonist for rightfully questioning Jenna's privilege.
Bat Creature[]
The bat creature is, without a doubt, one of the most arbitrary villains. It is described as fearsome and horrible, but the most damage it manages to wreak is on Link and Jenna's house and what little continuity the story managed to retain.
It appears towards the very end of the story, having followed Link and Jenna home and then attacking them in the night. Despite there being nothing about the creature that is any more incorruptible than the other opponents they've faced and despite the fact that Jenna has the power of the elements, Link has saved Hyrule and both of them are protectors of the Triforce, they still flee from it to Hyrule castle without making so much as an attempt to slay it.
This was clearly intended to add some kind of much needed tension and intrigue to the slow moving narrative, though LQ completely disregards logic and the rules of continuity in order to accomplish this. Logic and common sense would dictate that Jenna and Link would spring into action to quickly kill and get rid of it, much like a pest in the house, considering how powerful they have both been characterized to be. This would, of course, defeat its purpose entirely, forcing LQ to be a bit more resourceful in her 'lucid-dreaming'.