As someone that played stw for almost 4 years now i want to say that: buff that msk and his weapons.
You may ask, why would you do that? Here the reason:
So, to be able to fight the msk (if i remember correctly) you must complete the first 5/6 storm shields of Twine Peaks, be rank 122 or above, do a weekly quest (only way to obtain one of the 5 weapons) and be able to beat the king.
Edit + when msk got released superchargers didn't exist
That's a lot of work, but where is the problem?
Well, here are the problems!
Well for only a weapon that isn't even that much stronger compared to the events one and as the "hardest mission in the game* is beatable in solo, is a shame; how can te hardest mission in the game be possible in solo!?
Here is the "deal": buff both msk and his weapons to catch up the nowadays strategy; like buffing the base stats and "special ability" of the weapon.
Sorry if is messy, in my mind sounded super clear xd
Source: https://www.reddit.com/r/FORTnITE/comments/vuvhfk/mythic_storm_king_msk_and_his_weapons/