If you are not aware: Searing Arrows is an Orb effect, and a unit can only ever have one Orb effect active at a time natively in WC3. Some have priority and will overwrite others; Searing Arrows (and other auto cast attack modifiers) generally have priority over others. Examples of such Orb effects include Orb of Frost/Fire/Lightning/Slow/etc., Envenomed Spears, Liquid Fire, Lifesteal, Feedback, and many more things that modify attacks.
By giving this always-active Searing Arrows passive ability, you will disallow this unit from benefitting from any other Orb effect. If that’s fine and will not affect your map, then proceed as Uncle has shown. If that matters to you, you will need to find another solution.
To that end, I would suggest seeing if you can find an auto cast ability that will retain its autocast border status if the ability is disabled by a trigger or by a missing techtree requirement. It may be possible to ‘grey out’ the icon but keep the appearance of auto-cast. I would try things like Replenish Life/Mana, Frost Armor, Faerie Fire, etc. with something like this:
- Give the spell a techtree requirement of some custom unit-type, such that the spell can’t be cast unless the owning player has one such unit.
- Preplace one such unit on the map.
- On game start, manually order the unit to autocast the spell (by yourself, no need to muck with triggers).
- After it has been set to auto-cast, remove that requirement unit. You could make a trigger that removes it when you do something like enter a chat message or you could just kill it with another unit to be simple.
- See if the ability still shows as autocast.
- Instead of a requirement unit you could also disable the ability with the trigger action to do so, though in older versions of wc3 this does not have the option to keep the ability on the command card.
It may also just be worth your time to accept that the auto-cast border will not be possible on a passive skill. Why do you care specifically about showing this? If you are trying to imply something about its behavior you could make a custom icon with a different border (though it couldn’t be animated). If you actually want the Searing Arrows effect to trigger when the unit has enough mana, that’s another story. It is relatively easy to detect an attack and deduct mana from the attacking unit, if that is desired.
Exhume Corpses is a passive ability that can have a cooldown and mana cost. The quirks about getting it to cast ‘on-demand’ are detailed here:
Passive ability with cooldown - Best method!
Untitled Trigger 002
Events
Unit - Flametrooper 0001 <gen> Is issued an order with no target
Conditions
(Issued order) Equal to (Order(unflamingarrows))
Actions
Custom script: call IssueImmediateOrder (GetTriggerUnit(), "flamingarrows")
