Sprites are still overpowered

[Catwalk]

Hmm, it does sound like it would be difficult to balance that. Although, what if you make it a flying melee unit with that effect? If it's ranged it's crazy powerful, if it's melee only it might work. Another issue: Would the damage be the same whether you have 1 figure or 5? As in, when a unit of Swordsmen with Immolation attack a unit of Hammerhands, is that unit struck with Immolation once or 6 times?

Is it easier to make room for that than a Fairy Dust spell? I'm guessing you're looking in two different locations.

[Catwalk]

Another idea:

Flying
3 melee
4 shields
4 figures
2 health
3 moves
Armour Piercing
First Strike
Lucky
Missile Immunity
Caster 5 (letting it cast Resist Elements)

While that's a lot of abilities for a common unit, it adds up to being a lot of fun to play with. It won't do much damage, but it's guaranteed to do some. It's also quite hard to take down, requiring either strong magic attacks or a melee unit that can attack melee. It would be a useful garrison unit, and it would be a useful node defender too. And flavour-wise it would definitely feel like Sprites, difficult to pin down while busy making needle attacks.

[Seravy]

Hmm, it does sound like it would be difficult to balance that. Although, what if you make it a flying melee unit with that effect? If it's ranged it's crazy powerful, if it's melee only it might work. Another issue: Would the damage be the same whether you have 1 figure or 5? As in, when a unit of Swordsmen with Immolation attack a unit of Hammerhands, is that unit struck with Immolation once or 6 times?

Is it easier to make room for that than a Fairy Dust spell? I'm guessing you're looking in two different locations.

Once. Immolation is once per attack, like gaze.

Yes, it's significantly easier. Aside from attack flags having a free bit for the new ability, this one only needs the addition of, maybe, 20-30 bytes of code in the procedure where attacks are executed. (plus the display of a new ability icon and a boost to strategic combat value but those are not important)
Making it an activated ability would require
-Enabling the "spell" button if the ability is present for the human
-Implementing a new AI action code for using the ability
-Implementing an AI decision to use or not use the ability (like Fireball Spell etc)
-Implementing the effect of the ability for the human player
-Implementing the effect of the ability for the AI
-Implementing the effect of the ability for the Auto
-Keeping track of the ability getting used up in all of those cases
plus the ability icon on top of this all.

Your suggestion is interesting but I feel we would be looking at an entirely different kind of overpowered there. It's a unit that cannot be attacked by melee and range, has fairly good defense, high buffing potential, and despite all that, horrible for the AI (they aren't able to judge if an attack is safe or the retaliation kills the unit - they either attack with all fliers or none of them).

[Catwalk]

It has high buffing potential, but most of the good buffs aren't available to it. You can put Land Linking on it, but by then you also have access to awesome Giant Spiders. I don't think it would be terrible with the AI. They would use fewer for garrison (it doesn't have a ranged attack) and as harassment units they work far better than Sprites. You would not be able to win the game with this unit (you can now, as I have resoundingly demonstrated and am happy to provide further proof of), but it could play a useful role in certain situations.

As node defenders it's also interesting. It's not difficult to take out, but you'll usually end up with scratches. Maybe it should be speed 4, though.

[Seravy]

and as harassment units they work far better than Sprites

They don't. They are melee. They'll die in combat until there aren't enough left to allow attacking and trigger running away. At which point they most likely won't attack again the next overland turn as the stack is not powerful enough to do so.

The current sprites work because they have high enough overland rating (with ranged) to trigger an attack, but once they used up their ammo, their minimal stats make the AI avoid melee immediately, so the battle can time out and next turn they are back for more. This mechanism can keep working if they are ranged but do immolation type damage - we just have to make that attack flag apply AI combat strength to ranged power only.

[Catwalk]

As harassment units, enemy sprites get killed right away when they attack me. I don't leave my important cities without ranged defenses, so they go down like pin cushions. They very rarely present a challenge in my games. I want the AI to attack my units, more aggression is usually the better course of action. Especially if they have Armour Piercing.

I think it's a problem if they do the same damage whether they have 1 figure left or 5. That's extremely unintuitive, and I'll admit that I didn't fully know how the Immolation spell worked until you told me just now. It works for Fire Elemental because there's already just one figure. I'm open to all ideas of course, as long as it solves the present problem.

[Seravy]

I don't leave my important cities without ranged defenses,

Good. That means they achieved what I wanted them to. Most people won't bother putting proper defenders in their cities and sprites punish them for that.

[Seravy]

Allowing nodes to cast spells might be a good solution, probably hard to implement but it certainly cuts down the value of sprites a lot.
Some Aether Sparks at Sorcery, Fire Bolts at Chaos, and Fairy Dusts at Nature nodes...

[zitro1987]

Alternate Sprite Idea (minor stat tweaking, same purpose)

*To lessen massive ranged power boost while at nature node

0 to hit (-1)
4 figures (-1)
4 melee (+2)
6 ranged (+2)
1 armor/2hp or 3 armor/1hp (I removed 1 figure, so some added durability may be needed)

Normal battle:
Original - 0.4 * 4 = 5 shots, 1.6
Proposal - 0.3 * 6 = 4 shots, 1.8 (slightly more damaging to higher armor, slightly less damaging to lower armor)

Node battle:
Original - 0.4 * 6 = 5 shots, 2.4
Proposal - 0.3 * 8 = 4 shots, 2.4 (weaker in node)

[Catwalk]

I don't leave my important cities without ranged defenses,

Good. That means they achieved what I wanted them to. Most people won't bother putting proper defenders in their cities and sprites punish them for that.

But I always do that (in original MoM as well), and it has nothing to do with Sprites. This game is (still) all about ranged units, and it's foolish to rely on melee defenses alone.