MECHANICS

• Multiple custom spawning systems, enabling the obsessed to track you across unlimited distances - spawning itself near your location in optimal places out of your FOV, in a way that truly gives the impression of being stalked. Intensity is configurable and progressive, so once you are targeted, spawning increases gradually and reaches its peak after an hour. Spawns 4x more frequently at night. Smoke also indicates the presence of the obsessed, enabling it to vanish more effectively. If not targeted within the first 60 minutes (configurable) in your world, targeting will be forced once
• Mood/patience system from -5 to 5. Accepting its gifts or giving it golden apples (especially), poppies, and cooked meat increases mood, while attacking it, burning its gifts in front of it, or ignoring it for too long causes it to become irritable and decrease in mood. You can also craft a "cursed plushie" from gifts given by the obsessed: 2 "crushed animal remains", 4 "blackened sewer mush", and 3 "diseased ball of hair" items. 

• Chat message imitation: It can sometimes (poorly) imitate your chat messages (in its own chat responses) when present (1 in 10 chance per message). It aims to impersonate you directly by doing so. Not only this, but it can memorise up to six chat messages at a time and may repeat them later in its mimic mode, or even place down signs with them on.

• Advanced /obsessed debug commands: These enable easy bug reporting and let me check what is happening with spawns and transitions between modes.

• Powerful configuration options: Spawn rates are configurable, along with many other settings
• Multiplayer compatiblity: It can target one player max, or multiple players at a time if enabled in config, but only one will ever spawn at a time (you shouldn't have a bunch of them coming at once). If one-target mode is active, the obsessed will lose interest in players who are not present for long periods (configurable).
• Persistent per-target health across despawns and versions: You can kill the obsessed to gain a special item called the "Totem of Revulsion" with multiple benefits - repulsing mobs that attack you, preventing obsession targeting when in your inventory, and removing an existing obsession if consumed.
• Modular chaining mode system. It can switch between different "modes" dynamically, acting differently depending on mood and circumstances.
• Arachnoid forms: The obsessed will become increasingly arachnoid-like if you fail to keep it happy, eventually revealing its true form and scuttling around in a full spider form much of the time, slaughtering anything in its path. Prior to the true arachnoid form appearing, you may experience hallucinations of it.
• Look detection: It knows if you are looking in its general direction. It will react differently in response, and spawns should avoid occurring within your field of view.
• Patterned behaviour: Modes cycle in randomised shuffle patterns, guaranteeing that all of them appear, yet retaining unpredictability in the ordering.
• Highly skittish and elusive: Unlike most other horror mod entities, the obsessed does not get in your face regularly. It intentionally keeps its distance and attempts to observe you without being seen.
• Intricate adaptive sound design: The obsessed comes with a wide variety of creepy sounds, including chittering, crawling, scratching, hissing, and much more. It can even mimic your chat messages verbally (full text to speech system with two different voice options depending on mood). While it stays silent much of the time for a sense of mystery, it can shock you when it comes out with unearthly utterances. 

MODES

• Targeter mode: Naturally spawning version that you can encounter randomly in any biomes, including modded biomes. Upon getting close to this version and crossing its line of sight, you will become locked on as an obsession target. From then on, the custom spawning system works for placing the other versions around you dynamically.
• Initial mode: Stalks you, keeping at a distance, staring at you. Turns into another variant when looked at.
• Flee mode: Runs away rapidly, navigating over long distances until it gets out of view. An additional sprinting version of this mode can appear when the obsessed is unhappy. Spider version is faster and can climb walls in this mode.
• Corner (tree) stalking mode: Hides behind walls, and trees, peeking around the side to stare at you
• Crawling mode: Crawls around nearby, attempting to stay obstructed in the terrain and keep out of view, rummaging for resources. Occasionally, large clouds of smoke obscure its presence. Spider version exists for this mode - it can additionally climb walls and lunge at you to attack (then flees) if you get close.
• Staring mode (multiple versions): When it finds a good location to do so, it sometimes stands staring at you continuously, eventually fleeing. Later on, you may find it doing this in a spider form, coming with a lightning strike and forcing you to look at it briefly (along with an additional nasty surprise behind you).
• Swimming mode: If it enters water, it enters a swimming mode where it attempts to stealthily swim to opportune locations.
• Deposit mode: When it is happy, it occasionally may tentatively approach you to give you a wide range of custom item gifts. However, these gifts are not pleasant. Taking or consuming them improves the mood of the obsessed.
• Opportunistic mode: This mode can be triggered from other modes by two things. It can be triggered by certain other modes being near to an animal, leading to this mode running to grab the animal and carry it over to throw to you as a gift. Alternatively, it can be triggered if you are holding food items it likes in your hand when eligible versions are nearby. In this state, it comes over to you slowly, giving you a an opportunity to give it gifts and increase its mood.
• Mimic mode: Occasionally, the obsessed may mimic your movements, staying at a distance and copying your motions, including block placements (causing it to produce rudimentary structures).
• Jealous mode: When unhappy, the obsessed may become jealous and attack animals and other players near its target. Spider version exists of this form, which can additionally climb walls and attack hostile mobs.
• Build mode: The Obsessed has a dedicated mode for building complex structures. This advanced functionality enables it to build a variety of structures in your world, and you will see it placing every block individually to do so, even pillaring up when needed to place blocks at higher positions. It can build various preset structures (small lairs, webs, symbols), along with accurately imitating your builds (but without using valuable materials).
• Protective mode: The obsessed will sometimes protect its obsession targets if it sees them attacked. It will run in and attempt to kill whatever mob attacked you if it sees this happen, retreating if it gets to low health. It only does this when happy (positive mood value).
• Saviour mode: If the obsessed sees you trapped in a cobweb, it may run over to pull you out of the web with its own web shooting abilities, attempting to gain favour. This mode integrates directly with the "trap mode".
• Trap mode: A low-happiness mode where the obsessed spawns and creates a trap on the ground, filled with cobwebs. It then walks over to you, attempting to lead you into following it over the trap. Note that this trap automatically restores itself back to previous dirt/stone blocks after ~five minutes, preventing long term griefing.
• Abductor mode: This mode appears only when the obsessed is particularly unhappy. It attempts to navigate to you and grab you, forcibly abducting you and taking you away. You then wake up at home or in the forest. In future versions, this will lead to a it kidnapping you to its lair.
• Intruder mode: Another form of the obsessed that can appear when it is unhappy is the intruder, a version which locates your spawn bed and attempts to enter your house to rummage around, leave doors open, place wither roses, place a wide range of custom paintings, and change torches to redstone equivalents. It can also steal one item at a time (you get it back from deposit mode). 
• Enraged mode: Spider-exclusive form of the obsessed, only appearing if attacked multiple times by a player or tamed mob when below 150hp (out of its maximum hp of 500). This version is fully aggressive, attacking all players and animals (including even obsession targets!).
• Lurker mode: Spawns right next to the player when indoors and near their spawnpoint, ideally behind a window. Crouches and stares you down, running off if looked at directly.
• Threatening mode: When unhappy, the obsessed can enter a dark, brooding, mode that slowly stalks the player while displaying its spider legs. Getting close may trigger some aggression
• Spider lightning hallucination mode: Occasionally, when the obsessed is unhappy, you may see nightmarish visions of the obsessed in an arachnid form, hinting at its true nature.
• Spider nightmare hallucination mode: A semi-spider form can rush at the player at supernatural speed, grabbing them with its legs, as a creepy hallucination
• Surprise hallucination mode: Only visible to the targeted player. The obsessed can briefly appear behind you in a form that mimics the abduction mode, before disappearing moments later. 
• Surprise ceiling hanging mode: Rarely, the obsessed can appear on the ceiling, hanging upside down in spider form, when unhappy. It soon runs across the ceiling and then disappears
• Block breaking hallucinations: Upon breaking a block, there is a chance for the obsessed to lunge out of a surprise corner, providing an additional scare.
• Display entity: You can summon a display version of the obsessed that can play any animation on a loop, with any texture. Ideal for video-creation.

FUTURE MAJOR UPDATE PLANS:

• Lair structure: In future updates, a nightmarish lair will be added for the obsessed, and when it abducts you, that is where you will end up. It will not be easy to escape the increasingly aggressive and powerful arachnoid obsessed as it attempts to keep you trapped there - or you have the option to stay trapped indefinitely while it brings you food. Backstabbing it may be the only chance at escape, and this will truly irreversibly enrage it. Some possessive modes and planned mechanics relating to this major update are already complete.
• Ability to tame: In future, you will be able to tame the obsessed if you keep its mood high for long enough (this will not be easy, as its mood goes down automatically over time). The existing chat functions would work in conjunction with the tamed version, in a way that enables you to teach it to call mob types certain names - these could then be referenced to give commands - e.g. teaching it that chickens are called "birds", then you could say "bring birds" or "kill birds" and it would run off to collect or kill some - it would also work with hostile and modded mobs. Additionally, if you give it a nametag, it would learn to respond to that name. Accessories are planned, but exact details are yet undecided. It will be also able to build structures, plant crops, and mine upon request.
• Extended mood system: Current mood system goes from -5 to +5. In future, this will be extended to something like going from -10 to +20. Values below -5 would turn it into a highly aggressive and deadly forms, only accessible by attacking the entity or other acts that anger it directly. Values above +5 would work in conjunction with the planned taming system, opening up a new mood system where you can safeguard against it un-taming by keeping it happier, plus unlocking more modes and accessories at higher levels.
• Learning update: A future update is planned that would give the obsessed more learning capabilities, so it would adapt its behaviours over time based on situation, like the terrain around it and the player's activity patterns. Even now, it can adapt to most situations.
• MANY MORE MODES AND OTHER FEATURES ARE PLANNED FOR FUTURE UPDATES.