HelloDarkness07
First let me start off by saying great work keep it up, secondly from what I rember the soul stone sacrifice has to be someone close to you (iv seen some people useing a pet dog as a sacrifice instead of a human). for hela I'm not to sure what would be best for rn but in the future have her laze around Baldur castle watching anime is a fun idea.
Just a thought if you want to add hela to the harem or whatever things are going with the mc love life u can make hela a child that's not odins so her mom cheated on odin and he found out and decided to take his frustrations out on hela by making her in to a killing machine but the realising he went to far and banishing her to hide his shame.( you can change whT ever you like from this idea )
I believe giving hela the option of becoming, mortal is right at least for sometime - till main MCU begins, this will help hela to roam the universe, after all anybody wants to visit different places if he was stuck in one place for many years. plus, this idea is much better than having her hiding in solheim, because this will give MC sol avtar and Phoenix force the space and time needed to be a pair, if you consulting on making her.