Today I complained to my best friends how DMing is so much work, especially when you have to control spellcasters. Looking up all their spells and what they do and then decide out of sheer unlimited possibilities the best and most enjoyable action to take can easily take me 2 hours of my free time in play-by-post every single day.

My friend then voices the idea "Why not let such NPCs be controlled by external players?" and I thought this idea is actually pretty great. I'm sure there are people out there who don't really have the time or motivation to dedicate years of their life to a single Pen&Paper adventure, but would be willing to join in for a quick PVP battle. You would just need to build a community around that so there's always supply of such players when you need them. But I think it would make battles more interesting and take off work from the DM. Now I actually want to do that right away.