Slime

Being a descendent from the Great Slime Lord Rimuru you have inherited some of his more slime like traits 

Predation Stomach

Absorb the organic material of another. Doing so you roll a d4 for various side effects.

1- Suffer 1 level of exhaustion

2- Poisoned for 1 minute 

3- Fall Prone

4- Nothing Happens

After roll a d20 on the CR rating of the creature you are absorbing. If you roll the creatures CR rating, you successfully absorbed the material and my pick a feature or trait. To be decided by you and the DM. Having assimilated that trait you now have it permanently. You may activate the trait a number of times equal to you're proficiency bonus. The activation takes no action, and will last 10 minutes. Regain uses after a long rest. 

Liquid form

Due to being a Rimurur descendent you inherited his ability of shape changing. However, you are not a God... lol so your ability is a bit weaker. You are able to change your form in to what ever you see. However this does not give you any ability, trait or anything of the like. At lv 1 you may shift in to a medium target or smaller. At lv 7 you may shift in to large or smaller. 14 Huge or smaller. 17 Monstrous. Doing so is a bonus action and my be done at will. 

Future Attack Prediction

Once a long rest you may as a precaution assign yourself 3 resistances or one immunity. Once you have done this they cannot be changed until another long rest is taken. If you choose to change them you lose the first three. Must make your DM aware when you are using this feature. 

Demon Summoning

Once per long rest you are able to summon two greater demons under your control. You do not lose control over them unless another's magic interferes. They remain for 1 hour. the CR rating of the demons start at 6 and go up one per level after 14th. 

Perfect Form

Reaching the climax of your great power you are faced with two options. Once chosen you may not choose again.

1-  Regeneration

     At the start of your turn you heal 2D10 plus your spell casting modifier with out fail. 

2-  Mimic

     From your great list of acquired traits you may choose two to merge and create your own unique skill. Usable once. Work with the DM to figure out your skill.