On the U.I you should have a box where you can change ammuntion type, for example, explosive arrow to snake arrow etc… by clicking on an arrow near the box
Demon lord perk - being able to switch it on or off at your discretion, in my opinion its an awful perk to spend 20 points to get a wandering idiot, however if you can turn it (ON) when you (DONT) have a thrall or pet active etc that could be something useful.
In my opinion with demon lord for its cost it could be a single (controlled) pet you can summon to follow and fight for you as long as you don’t have another follower with you, it would start at level 0 and permanent but will despawn if you choose another follower. The benefit of this would be that you would always have access to a follower, if the demon dies another will respawn in its place at 0, this would function a bit similar to elder scrolls online druid which has the option to have that bear and respawn it. For a level 20 perk this would be much better.
Thankyou for reading.