Host of Mushrooms

You have ingested a primordial myconid; one destined to make you into the scion of a great myconid colony. Mushrooms now bud from your body and share their wisdom. 

Note: this feat is the basis for a whole character of mine, so it is very dense.

The parasites spell save DC is equal to 10 + your proficiency bonus + 5.

The myconid begins its growth on your back and neck. It's mechanical features are as follows: 

Pariah - The unenlightened cannot endure the sight of your budding greatness. When the mushroom growths are plainly visible, you have disadvantage on all charisma-based skill checks; however, social interaction with another myconid or mushroom entity bolstered by the growth. You have advantage in such situations. 

Whispers of the Hivemind - Intermittently, the parasite will share a secret with you. This secret could be anything from social advice based on a "detect thoughts-like" phenomenon (in fact, your DM may elect to leave this up to the parasites spell DC) to the location of some allies to the myconids. The parasite may also lie to you, plant seeds of paranoia, or otherwise plot against you - for reasons unknown to you. 

The Ascension -  Every level (or milestone of any sort, at your DM's discretion) the parasite advances. Roll a d6; the mushroom growths will spread either up, down, or left/right from the center of your back. These growths will impart the following changes to your being. They are demarcated by 1/2/3, meaning the first, second, and third occurrence of this outcome, respectively. If you have 3 in a direction and roll it a 4th time, reroll. 

Up (5-6 on the d6): 

1. The growth reaches the side of your face. Hiding the growth becomes harder. You have disadvantage on checks meant to conceal the growth, unless it is completely concealed by your clothing. The frequency of Whispers of the Hivemind greatly increases, and you have disadvantage on wisdom saving throws to resist its will, should it impart a direct command. Your ability to discern friend from foe weakens, and you become more vulnerable to any suggestion from the parasite that someone is plotting against you. 
2. One side of your face is so engulfed by mushroom growth that you practically wear a crown of mushrooms on one side of your face. Helmets and hoods become more awkward to wear, and unless custom gear is created for this function, concealing the growth will always impart disadvantage on any check meant to do so. You may now cast "detect thoughts" once per short or long rest, with the parasites spell save DC. Your saving throws to any spell or effect meant to alter your state of mind, like a charm or detect thoughts spell, are now dictated by the parasite's wisdom modifier (5). 
3. Your entire face, and eyes, are covered by the mushrooms, which now protrude above your head. Concealing the mushrooms is now extremely difficult. Distinguishing the will of the parasite from your own is almost impossible - as you become one (or perhaps you are lost to its influence entirely). You will develop a strong urge to find a site for the colony to grow, as you are nearly an adequate host. Reach at least two in any other growth direction to become the perfect host. You may now cast "create undead" once per long rest, provided that the corpse in question retains some sort of central nervous system. You can only communicate telepathically with any being that is either infected by your spores, which automatically happens whenever anyone fails a wisdom saving throw against your parasite's spell save DC within 10 feet of you - you need not speak the same language as your target. Spells do not require verbal components to cast. You may want to discuss psionic casting with your DM.

Down (1-2 on the d6): 

1. The growth reaches your waist and upper legs. You gain disadvantage on acrobatics checks. You can now cast a limited version of "fog cloud" once per short rest, which only reaches within a 5 foot radius of you. Wearing pants can now become burdensome, as these mushrooms are very tender. When destroyed, you suffer 1d8 poison damage, and you cast "acid splash" as a reaction. You may be unable to wear some lower body armor, at the DM's discretion.
2.  The growth reaches to your knees on both legs and your entire back is covered. The mushrooms harden, granting the effect of "mage armor" at all times. Most armor will be unwearable. Your movement range decreases by 10 ft. You may incur unvoluntary movement patterns from your parasite, causing you to be visibly peculiar in the open world. Even if hidden, you may incur a disadvantage on all charisma-based skill checks against all "ableist" inclined individuals. 
3. Your entire chest and lower body are covered in hardened mushrooms. You may now cast acid splash as an attack of opportunity. You are also immune to poison damage. Your movement range increases by 20 feet. You will experience bouts of lost bodily agency to the parasite - resisting this will require a DC 17 strength saving throw. You lose your disadvantage on acrobatics checks. 

Left/Right (3-4): 

1. Your arms and shoulders become covered in mushrooms to the elbows. These are sensitive mushrooms, rendering any armor that contacts this area unwearable, unless customized. You gain disadvantage on strength checks. Anyone who contacts your mushrooms will have to succeed a DC 15 constitution saving throw, or be poisoned. You will occasionally find moving your arms difficult when the mushrooms have alternative plans, when attacking or casting a spell, in such instances, make a concentration check or "fizzle" your attack or spell casting.
2. Your arms are covered to the wrists. You will more often lose control of your arms, for the same check as above. However, you gain the ability to use "action surge" once per day - not allowing for any additional movement.  
3. Your arms are completely covered. You may be unable to cast spells not from this feat - perhaps discuss a class-pivot or psionics with your DM. You lose disadvantage on strength checks, and now gain advantage. Your climbing speed increases by 10 feet. Your may now cast "ray of sickness" with your parasites spell save DC, once per short rest. Any creature within 5 feet of you must succeed the above constitution roll to resist being poisoned. If you have also reached at least "2" in the "down" category, you are now further eligible to become bruiser figure - discuss this with your DM.