Step 1: Monster.
Eboneyes - Tiny aberrant creature - Level 5 Controller Leader
An eboneyes (a single creature, despite the plural) is never encountered alone. It is always found bound to a host, usually an intelligent evil humanoid spellcaster. It appears as pure black eyes, without whites, iris, or pupil, in the place of the monster's normal eyes. DMs should make it clear to the players that this is unusual for this monster type and should be investigated (see eboneyes lore).
HP 44, AC n/a, Ref n/a, Fort n/a, Will 18 (see Bodylack).
No Basic Attacks - The eboneyes cannot take opportunity attacks and cannot, by itself, provide flanking (or any other effect requiring the ability to attack) to its host's allies.
Bleak Curse (Standard action, at-will) - The eboneyes places a Bleak Curse upon the nearest visible enemy. While under a Bleak Curse, the target takes a -1 penalty to its Will defense.
Clouded Vision (Immediate reaction, at-will, when a creature under the effects of a Bleak Curse is damaged by the host) - The target treats all its enemies with concealment as having total concealment, and all other enemies as having concealment, until the end of its next turn.
Irrational Panic (Standard action, at-will) - Targets one visible creature suffering a Bleak Curse; +8 versus Will; the target must take one of the following actions, if it can. Extinguish a light source it carries or can easily reach; attack an ally bearing a light source, if that ally is a legal target for the chosen attack; move its speed toward a space with less light than its current space.
Bodylack - The eboneyes is not an independent creature, it's an intelligent magical effect/entity bound to a host. As such, it has no AC, Reflex, or Fortitude defenses. It is completely immune to effects which target these defenses, although frequently it will be affected (such as by a teleport) because the host has been affected. Its Will defense is listed above, as is its damage resistance to all but psychic and radiant damage. If the eboneyes' host is killed, the eboneyes becomes helpless, and may be extracted (along with the host's eyeballs) and moved freely.
Eboneyes lore:
Dungeoneering DC 15 (remember, lore about aberrant creatures is Dungeoneering) or Arcana DC 20 - An eboneyes is of the same class of creature as an arcane familiar - it is an embodied spirit, in this case embodied in the owner's eye. A willing eboneyes can be bound by any character, using the Eboneyes Familiar feat (see sidebar, or in the case of this post, end of post).
Step 2: Item or room (DM's choice)
(Some PCs may have other access to telepathy, in which case that means may be used to communicate with the eboneyes instead. The eboneyes is incapable of communication via anything other than telepathy.)
Scroll of Inner Speaking - Takes 5 minutes to enact, and 80gp worth of arcane ritual components. User can communicate telepathically for one hour, with a range of touch. Give this to the PCs in treasure after they've discovered the eboneyes and at least had a chance to investigate it with lore skills.
OR
Chamber of Minds - This oddly-shaped room has walls of thinly beaten lead, worked all over with large runes, which are in turn worked with smaller runes, and they with smaller ones, down to a finer scale than the eye can see. Any creatures inside this room may communicate telepathically with one another for so long as they are both in the room.
Step 3: Skill Challenge.
"Well, now. You're cleverer than you look, aren't you. Yes, the rumours you have heard are true. I can be bound, and lend you my not inconsiderable aid. If I want to. So start talking... what do you think you have to offer me?"
This is an Arcane/Diplomacy/Dungeoneering skill challenge of moderate difficulty. If using the Chamber of Minds, then a standard skill challenge (personally I much prefer Stalker0's Obsidian rules to the core skill challenge rules, but either would work) is appropriate. If the PC is using the Scroll of Telepathy or some other single-speaker means, then use a series of individual skill checks. I strongly recommend that a well-played scene, even without skill checks, should be permitted to serve here instead, but that's up to the DM.
Failure should not prevent the eboneyes from agreeing to be bound... but it means that its agreement comes with a higher price. It can exact prices in healing surges per day (taken at the start of each day), in XP per encounter (5% is not, actually, despite what the PC may opine, the end of the world), or in the form of some other commitment from the player. Note that the eboneyes retains its monster statistics while bound, and although it cannot attack its host, it can target his companions freely, as well as withdraw or impart its familiar-granted benefits as appropriate, entirely at its own discretion... so a good working relationship is essential.
This feat may not be retrained until a Remove Affliction ritual is performed; the DC for the ritual check is equal to the owner's level at the time of the binding, plus the eboneyes' Will defense.
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Feat: Eboneyes Familiar
Prerequisite: A willing eboneyes; you must possess two working eyes.
The eboneyes (see monster entry on this page) has been bound to you in a manner akin to an arcane familiar. This feat is mutually exclusive with the Arcane Familiar feat, but a possessor of the Arcane Familiar feat may retrain this feat into the Eboneyes Familiar feat immediately (without needing to gain a level) as soon as the DM is satisfied that both the player and the eboneyes are willing. It is recommended that a suitable ritual be roleplayed for this purpose, but in game terms this does not require the Ritual Caster feat nor ritual components.
All of the usual rules for Arcane Familiars apply, except that the Eboneyes does not possess an active mode; it is permanently bound to (and replaces the appearance of) your eyes. Feats and powers which can affect Arcane Familiars in passive mode will have the same effect on this familiar.
Eboneyes Familiar:
Movement n/a, Perception +9 Darkvision (inverted as below).
The user's eyes appear uniformly black, without pupil, iris, or white. The user may temporarily suppress this effect with a Wisdom or Charisma roll (plus any bonuses other than stat and half-level to the user's Will defense) against the eboneyes' Will defense; this also suppresses all of the eboneyes' constant benefits, and lasts at least until the user returns to deep enough darkness that they can see no light or light sources whatsoever - possibly longer if the eboneyes doesn't accept their excuses as to why.
Constant benefits -
- The user gains darkvision. However, the user's vision becomes light-inverted, and objects and creatures in bright light gain total concealment (equivalent to a character with normal vision attempting to see in total darkness), and objects and creatures in dim light gain concealment (equivalent to normal vision into dim light).
- The user can communicate telepathically with the eboneyes. The two do not automatically share information except as normal communications allow (and the eboneyes is willing to share), and they do not share senses.
- With a minor action, the user can request that the eboneyes use one of its creature powers (akin to commanding a summoned creature, see PHB2 page XX). However, the eboneyes (as roleplayed by the DM) need not comply. Note that for the sake of keeping the game running smoothly, the eboneyes will generally not enter into conversation about its compliance or noncompliance until after combat is over; at most it may give a short one-sentence complaint in place of using the ability.
- If you have the Warlock's Curse ability, then as part of the minor action to place the Warlock's Curse, you may also request that the eboneyes place its Bleak Curse on the same target. When you deal your Warlock's Curse extra damage, you may use an immediate reaction to request that the eboneyes immediately use its Clouded Vision power on the same target.
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What does an eboneyes want? That... that's the part that's up to the DM.
But my question would start with... how exactly does something that is a familiar in all but name end up going "feral"? And how would it relate to things pertaining to its former master - or even its descendants, or things that remind it of same?
And just how cunning and cruel is it? Enough so that it would aid someone faithfully, until just the right moment?
Postscript: For strictly satisfying the challenge in this thread, this might seem like four steps. If so, treat the Feat as the third step; either group the "getting ability to communicate with it" and "communicating with it" into one step, or omit the skill challenge and just roleplay the interaction instead.