It is complex to explain but I will try my best, if you opened the map right now however and don't know what your doing you won't get any answers, lets start with the basics.
Without any ai scripts if you charge against an enemy unit with a dark archon around not mattering if the targeted unit you were going for was the dark archon himself or a different unit of the same player it would maelstrom you before you come close to reaching your target that's assuming you both have vision of each other thats the common thing we know about dark archons, now some of this you guys MIGHT not know.

without any ai scripts if you right click on a beacon owned by the dark archon it will maelstrom you, sometimes it takes more than 1 click but it definitely will maelstrom you.

With the first thing I told about charging against an enemy unit that is of the same player of the dark archon and it would maelstrom you, but if you ran up to the enemy unit without using the "attack" command but simply moving around it, it wouldn't maelstrom you at all, or even if you were up close to the enemy unit after wards then deciding to attack it, the dark archon wouldn't maelstrom because then it would maelstrom it's own unit in the process, this goes the same if your unit was next to the dark archon, the dark archon also wouldn't maelstrom you consistently if the dark archon was facing another direction if you were near it.

With the ai I used in the map however, I've tested for protoss units that if your protoss unit normally has more hp than the unit that it's going to attack, it wouldn't maelstrom you until the unit being attacked has lower hp than the protoss unit due to hp % modification, it would then maelstrom almost unconditionally if being attacked even if it means to maelstrom its own unit in the process or if your unit was next to the dark archon where all this wouldn't normally happen without the ai script.

The next thing is you have to have more hp than the targeted unit with your protoss unit as well as having the shields same as the hp. for example charging unit : zealot with 8000 hp and 8000 shields -> targeted unit : marine 7900 hp, with the ai, even if the marine was next to the zealot it would still maelstrom, this can be useful in maps if say you have a bunch of protoss melee units walking around and you have dark archons, shutting off the shields to 0% as a regular basis and if the moment to intend to maelstrom you can turn on the shields to 100% triggering the maelstrom process. with the ai.

If you use a hydralisk to attack the unit it would maelstrom unless the units are close together, or if the unit being attacked has a lot less hp than the hydralisk. another theory i tested was that if you used tassadar the templar attacking lets say a marine, there would be quite a gap between them but even so the dark archon won't maelstrom you (in process of already attacking unless you move a protoss zealot (doesn't matter the hp or shields or if it was hallucinated) simply make it move around the tassadar unit whether or not your using the "attack command" and simply walk away, if done right you will see that the dark archon actually maelstroms the tassadar instead of the protoss zealot despite that you were using the protoss zealot to trigger this. Another useful thing is that if you were to use a tassadar to replace the maelstrom spell in a game you could, I've tested that if you were attacking the enemy unit with tassadar (assuming both units have around full hp so the dark archon won't maelstrom because of the depleted hp). and you simply use 'hallucinate" on the enemy unit, the dark archon would maelstrom the hallucinations and also the enemy unit in the process. this can be useful to replace hallucination with maelstrom.

there might be some things i forgot to list in here, remember to use the siege tanks to "siege" or "unsiege" to modify the shields of the fenix zealot and the dark templar for differences of if the maelstrom would cast, DO NOT FORGET TO "MOVE" UP TO THE ENEMY UNIT BEFORE ATTACKING IT OR ELSE THE DARK ARCHON WOULD MAELSTROM YOU BEFORE YOU GET TO THE TARGET AND THIS WOULD LEAD TO TROUBLESOME TESTINGS DUE TO THE FACT THAT COMPUTER UNITS TEND TO ALL TARGET MAELSTROMED UNITS.

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You should make a cliff note on this. I doubt anyone would really want to read all this.

true, =/ i'd be glad to demonstrate anyone how its done though, just ask o.o.

I'd read it if it had punctuation. I gave up after the first two sentences (paragraphs).

Yeah you really need to like copy paste this into microsoft word for spelling/grammar corrections. It's hard to read. And you're not really telling us anything new. We all know you can provoke spellcasting units to cast their spells on you.

i've just found out scmdraft reads "Run Ai Scripts at Locations" different than other editors, as in their labeled differently, I never paid much attention XD, but.. really? everyone knows how to make a dark archon maelstrom its own units and manipulate the da when to maelstrom through the entire process of attacking the unit? without moving a single inch of the attacker that is or adding any other units in the game.

I didn't read this yet, but I think a map of Falkoner's named "Spell Reference" has this idea.
I saw a dark archon casted maelstrom. I don't have the map, btw.