how hard would it be to make something like the shadow monarch from solo leveling?

thinking it could have a general passive skill tree for combat and for the shadows

idk how hard it would be to make but it would be cool to be able resummon monsters you killed as your shadows boss monsters are immortal but normal shadows only revive a few times before vanishing (one of the passives allows you use your own mana to recover them)

thinking the shadows draw aggro better then the player

(also thinking for skills at least)

arise (to raise shadows thinking each point you put in boosts the range)

stealth (toggle it slowly drains mana but makes monsters target your shadows before you)

monarchs domain (a aura that boosts your shadows and other players if it works in mp XD)

could add the speed boost as another toggle (forget its name)

or the dagger attack he does

o and the shadow spiritual armor thing he does close to the end (its a toggle that boosts your armor and mana)

o a passive could be the black heart (witch boosts your mana by a percent)

idk past that as i am unsure if you could connect your shadow limit to your level