I've changed the ember mage toggle skills with mongol archers...however, I find them not appropriately beneficial to vanilla classes. I'm inspired with your idea to make them boost weaknesses into strengths.
Yes, because it requires a little change and addition to the skill effect so that it can be appropriately beneficial to vanilla classes
While trying to understand the complex toggle system of these new skills, I worry and interested to find out how effective it is. Let me give you the premise of how these skills work.
Main skill simultaneously desummons, remove buffs, and summons an invisible pet that casts an aura to give buffs to any friendly unit who gets hit first (but most likely it would be the player due to the range is 0 to 0.5 and Pet is attached to player, center position). The buff includes a limiter, that way, the unit won't receive the effect in stack (would cause the game to lag if not done).
Here're my concerns, does the skill effectively desummon the invisible pet and does it not effect other summoned pets/minions? The skill does not point out to a specific unit, it just resummon it while attaching an affix to desummon any monsters. Its either my memory in modding is rusty or I just didn't encountered something like this before. As you know, I have a mod that allows summoning another customizable pet and that pet can also have their own pet and summons. It is already very much complex, that's why this toggle skills of mongol archer intrigues me.
Is the method used in the toggle skill bladedancer different from the one in the archer mongol?
Hmmm, when you explained that I also remembered if the toggle skill on the Mongolian was different from the others. Can you also check the toggle skill that is in the Prophet (Variant Class) class, because the skill also has a toggle skill even though it can't be turned off after use.
There are also toggle skills in other classes such as Plaguelord. I think the method used by Plaguelord is similar to that of the Mongol archer.
Note:I had an idea but it didn't seem good. If the toggle skill is quite complex and problematic, it is possible that instead of making it toggle we can extend the duration of the skill. It does look bad but this might be the last solution to get a long buff. Or make it like the one in the Prophet class, after the skill is active then the skill cannot be turned off (But it can be replaced with other toggle skills).
P.S. I'm not sure about the request to add new effect on General Skills, the bleed effect feels inappropriate for the minions and the potion effectiveness and pet travel time, I think should remain item exclusive bonuses. Otherwise, we're gonna have all the bonus effects in the game's effectslist activated in our general skills. Makeover for the elemental guardians should be our last priority.
My idea is to give a bleed effect to the Pet so that it feels real and gives a little help to the player. Because I see a lack of effect that can support pets. For example, We cannot provide gems or enhance with weapon effects on pets because pet collars & pet tags are armor types.

For makeover for the elemental guardians It should be our last priority, I agree

. Because there are still many problems that are far more important than that.
IdeaIf you see the skill used by Kensei class (Cold Steel, Heat of the Forge, Storm Blade) I think the effect of the skill is suitable to be used as toggle skills.
But on the Cold Steel effect & Heat of the Forge which when killing enemies, the enemy will explode. Can it be made so that when the enemy explodes the surrounding enemies are affected (like burn, and frozen)?
For Heat of the Forge skills may be it can be combined with skills from Monster Hunter - "Heavy Support". It would be cool if we were supported with missiles when we attacked the enemy and would explode when they hit the enemy. For explosion animations can be taken from Mongol Archer - "Exploding Arrow"