It's capable of quickly regenerating the body to its default state. If imbued into magical clothes or armor, it grants a self-repair function that enables a complete recovery of the clothing even "from scratch".

Short and long rest restores lost limbs, bodyparts and as well as damage.

you take half damage from non-magical slashing, piercing, and bludgeoning. And you feel no pain. However, you still take damage.

Thermal fluctuations resistance
You are resistant to temperature-related damage. (fire and ice, heat and cold immunity)

paralysis immunity.

Unlike other slimes you do not store items in a physical location more a pocket dimension anchored to your body and thus do not lose carried items.

with a few minor differences, one you can carry 1500lbs in your stomach. Your stomach can analyze, copy, manufacture and refine and process whatever is inside it. Or devour it for spell slots. common items restore spell lvls 1-3, uncommon items 4-6 rare 7-8 and legendary lvl 9 slots. living creatures depends on the magic they have inside them. for example a wizard with spell slots for spell lvls 1-3 unused will relinquish half to restore used slots and half to increase capacity. there is no limit however Mystra or some other deity of magic may take notice and react to you, how is up to dm. 

In addition, the user is able to observe how waves disturb the nearby magic, then use that information to calculate the visual, auditory and other wave-based information of the surroundings. Magic Sense also grants the ability to understand and express the intent of spoken words even if the language of the conversation partner is unknown.

• Magic Sense enables users to be aware of their environment in battle even if blind or deaf and has advantage against surprise attacks.

  However as magic is required for this to work, magical dead zones. Anti-magic field and similar effects render the slime deaf and blind leaving only touch and tremorsense.

   you gain True sight, True hearing up to 60 feet in all lighting conditions, as you are not using light but magic to see. 

you do not need sleep, to eat or use the toilet. you don't breath. you don't gain exhaustion levels, however in compensation your state is directly tied to your magic slots. when your magic slots fall to 0 you immediately enter sleep mode forcing a long rest. as a slime you are mute until you consume a creature capable of speech.

through the death of 10000 creatures total. You will fall asleep and evolve into a powerful being. You gain +5 to all attributes and your skills will evolve.

Note: killing a creature who has killed a number of people already adds their death toll to yours.

It allows any parts of the body to be transformed into any parts of the bodies of species that the user can transform into. Multiple such partial mimicries, even of different species at the same time, is possible. however, mass rules still apply

you lose access to magic sense and gain touch taste and sight of the consumed humanoid. You also gain snippets of their memories you may relive while in sleep mode and some of their proficiencies decided by dm.

Though androgynous due to your lacking of a gender, your appearance is almost exactly the same as the one you consumed, excluding stature which at first is child like, aging in 2-3 years every 5 levels. Depending on circumstances of this consumption, this can earn you the enmity of friends and family of the being you consumed.

You either store, break down for spell slots or refine and process(EX. ore to metal). You can consume a creature whose CR is within 1/2 your character level rounded up. After consuming your foe you gain 2 prime traits from its status charts. Ex. Spiders web walk. and you gain all vision and movement abilities that you do not have.
After analysis by Great sage, you gain any spell they had for which you have spell slots for and you also gain half of each level of spell slots they had.

While the creature is alive and engulfed rolls of 10 or higher on a d20 activate this effect prematurely.

• Stomach: Stores the predated target. functionally infinite, It can also store materials collected or created via Analysis. Items stored in the user's stomach are unaffected by time. 
• Mimicry: Reproduces the form and Skills of absorbed targets. Only available once the target has been fully consumed and Analyzed. most intrinsic Skills gained from a predated species can only be used at full capacity by taking the form of said species. For creatures larger than your size you must spend spell slots to compensate for missing mass. X number of spell slots equal to cr+1 per size category above your mass. This ability can be used in and out of combat, while in combat once per round you can change form as a bonus action.
• Mass: your mass increases one size category every five levels, you count as that size category for all checks excluding movement. however, your physical size category remains small.
• Isolation: Stores harmful effects incapable of being analyzed, neutralizing them, and breaking them down into magical force. 

all your abilities are derived from your race and those stolen from other creatures you consumed.
You start with 20 hit points
And after 1st level 1d6+con
You must consume a humanoid(human, elf, half-elf, dwarf, Dragonborn, halfling, gnome.) before you can take a class. You do not gain the consumed person's class. You have a chance to steal their feats roll a d20 at disadvantage 10 and over you succeed in taking their feats.

• Hasten Thought: Boosts perception speed by a thousand times. Learning, analysis and other thoughts are sped up starting from level 3 you can uses this to add your INT modifier to your AC and your initiative rolls.
• Analyze and Assess: Analyzes and assesses the target. Analysis takes 1 hour per cr of the consumed for each extra ability over the first 2 or 10 minutes per rarity level of item.
• Parallel Operation: Operates on any matter the user wishes to analyze, separating it from the regular thought process. Any process under Parallel Operation is affected by Hasten Thought and accelerated by a thousand times. research takes less time as per the results of a roll on a 1d100 as percentile dice.  
• All of Creation: Provides full coverage of all non-concealed phenomenons. this taps into the world and provides answers to any questions asked of the great sage except those concealed. ultimately the gm decides which info is available to great sage.
• Analysis: Analyzes and researches targets that are taken into the user's body. Lets the user create craftable items as with tools and workshops. If the required materials are present, allows the user to make a copy of the item. Successful Analysis of the casting method allows the user to learn the target’s Skills and Magic.