What are Rimuru's power in the manga or web novel? I kinda remember someone saying that Rimuru can make a whole planet and life forms on it.  Can anyone check this and if true what chapter in the manga or web novel?
SlimeViscous Organism: As a Slime, Rimuru is a monster that doesn't need to breathe, sleep or eat, as he can survive only on the magicules in the atmosphere.

Intrinsic Skills: As a Slime, Rimuru has the species-specific Skills of Absorb, Dissolve, and Self-Regeneration. These are later fused into Unique Skill Predator to create Extra Skill Ultraspeed Regeneration.


Absorb and Dissolve: Slime-species intrinsic Skills that are inferior versions of Unique Skills Predator and Glutton.
Self-Regeneration: Allows the user to regenerate from injuries which include regenerating lost limbs. An inferior version of Extra
Skill Ultraspeed Regeneration.


Demon SlimeDemonic Viscous Spirit Body: As a Demon Slime all his bodily attributes are greatly enhanced. He can freely change between a material and a spiritual body.

Intrinsic skills: As a Demon Slime, Rimuru has the species-specific skills of Infinite Regeneration, Control Magic, Multilayer Barrier, Universal Detect, Universal Shapeshift, Demon Lord’s Haki, Enhanced Replication, Spatial Motion, Darkflame Lightning, and Universal Thread.


Infinite Regeneration: Enhanced version of Extra Skill Ultraspeed Regeneration. Works even quicker than its previous
version and can now even regenerate from having the Spiritual Body
shattered.
Control Magic: Same as its Extra Skill version, but further enhanced.
Multilayer Barrier: Same as its Extra Skill version, but further enhanced.
Universal Detect: Multi-purpose Sense-Skill that contains the effects of other Sense-Skills like Magic Sense, Sense Heat Source,
Sense Soundwave, and Keen Smell.
Universal Shapeshift: Same as its Extra Skill version, but further enhanced.
Demon Lord's Haki: A Skill that enhances a magic-based creature's Monster Aura. Needs to be at least on the level of a
Demon Lord Breed to acquire. This Skill is a composite of several
other Skills like Coercion and Magic Aura, among others. It causes
Fear and can even cause instant death to those who can't resist it.
Enhanced Replication Improved version of Replication. Capable of being used as an incarnation medium for True Dragons.
Spatial Motion: Same as its Extra Skill version, but further enhanced.
Darkflame Lightning: Enhanced version of combined Extra Skills Dark Flame and Dark Thunder.
Universal Thread: Enhanced version of Sticky-Steel Thread.


These are just physical aspects, there are far more powers than I can list, check out the wiki

source: https://tensura.fandom.com/wiki/Rimuru_Tempest/Abilities_and_Gears