Strength and con scores are halved, and cap at 10. Dex increases by 4 and Int by 2.

You live just as long as humans.

You are the the same size as a regular cat (tiny).

Your base speed is 40, and you have 30 climbing speed.

You have dark vision with a range of 60, and You gain advantage on perception checks.

You may add your proficiency bonus to any dex roll that doesn't require hands and you aren't already adding your bonus twice.

You can't be knocked prone by falling, and when taking fall damage, reduce the damage taken by your dex score to a minimum of 0

You speak common, but not easily. The DM may choose a number or words of phrases you don't understand or might miss interpret, or have you make rolls during conversations.
You also speak many languages of nirn, but that isn't very helpful out here.

You dont have hands. 

[NOTE: im putting two versions here due to telepathy being different in the d100 campaign and dnd]

A: You can telepathically communicate with a number of creatures up to you spell casting modifier within 120ft. this is a two way connection, and does not require line of sight.

B: You can telepathically communicate with any number of creatures you can see. this is a one way connection.

Your soul is a well of infinitely replenishing energy of another world. you have a number of energy points equal to [?], which replenish after a long rest. Other means may replenish energy at the DM's discretion.
Energy can be used to:

- cast spells without needing some or all components.

- cast spells as one level higher (used with a slot)

- cast cantrips at higher levels

- alter a spells effects

- create temp spell slots

- other things at the DMs discretion

- probably some funky stuff with the afterlife and resurrecting

using energy in these ways is unreliable and unstable. What exactly happens is up to the dm, but and easy solution is rolling the wild magic table (replacing sorcery point effects with energy, or artifact property tables.

you may also use your own blood as a substitute for magic inks, at a rate of [?]hp=1gp.