Hi, got some more ideas if you want some interesting things for sound RTS, which is obviously a great and fun game without them. Just putting them here to see what you all think.
Pain sounds that units can play when they lose health, maybe even different sounds depending on how much damage the unit took.
The ability for units to explode on death and harm near by units.
The ability for units to react to being damaged, probably by countering, boosting defense for a limited time, or flying to the air or landing on the ground to avoid the other attacks if possible.
The ability for attacks to apply unit specific effects to things they hit like poison to remove percentages of hp or paralysis so they can't do anything at all until it goes away, or both?
Allow mod writers to tell the AI what some of the spells and mana based abilities are for, at least the ones for summoning so then the AI can use them to complete instructions you write down in the AI.txt file like it does with some normal recruit and upgrades.
Allow attacks that drain mana?
All I can come up with for now haha.