Spell Ideas -- are they possible?

Working on a massive RPG with my friends and I have a TON of custom spells/abilities. Some of our ideas are a little crazy though, so I've come here for a bit of help for some of my ideas that I dont have the knowledge to create.

Soul Drain - ability targets all friendly units and drains some of their life to deal dmg to an area of enemies. The dmg is dependant on the ammount of life drained from allies.
Basically with this one I invisioned the hero to target a group of allies with some sort of AE target ring and whoever was in that ring would contribute to the dmg agaisnt the enemies. I really have no idea how I would pull this one off.

HP+ buff - is there any abilities/spells in the editor I could base off of to make a straight increase HPs buff? I can only think of using some sort of +STR ability.

Defend / Magic Defense -- do they share the same base? For instance in the editor for magic defense, for the damage taken values does it only pertain to piercing attacks? I wanted to come up with 2 different skills; defensive stance and offensive based off these abilities or similar ones.

Manaburn -- not like the one in game, but rather this ability takes all the remaining MP from the caster and deals dmg to a single target dependant upon the ammount of MP used.

Detecting a passive ability -- for example, is ther a trigger that detects when a passive skill like evade activates?

I may have some more, I will edit this message later. THank you for any help.

Soul Drain: Yes its possile... when the spell is cast, pick every unit and drain the amount of hp and add the amount of hp drained on each unit to a variable so when the picking loop is finished you have a variable of the amount drained. Then you pick a number of enemy units nearby and distribute the damage (split the variable in number of enemy units picked) and deal that damage x2 for example (will damage twice as much as you take).

Hp + buff: No, i dont think you can without the use of upgrades... might be some simple ability for this, i just cant think of any atm

Defend/Magic defence: What do you mean? You could use 2 defends on one hero, the only thing that is messed up is the command "Unit - issue order with no target" where you cant know which one of the defend's u use. But otherwise theres no problem using defend for both offensive and defensive.

Manaburn: Thats a easy one, Just deal the differetn between current mana of caster and 0 and then deal that damage to the enemy (and delete the mana remaining).

Detecting a passive ability: Yes there is, there is a map somewhere on these forums (made by vexorian i think?) that can detect when a passive ability is used. It works by using the same random system as the game i think....

I may have some more ... blabla: Okay, ill check back once you update then :)

I will hopefully answer some of your questions.

#1: I have no clue how to do this, but my guess would it would be done through triggers, and many buffs.

#2: Easy, create a ability which is based off the item, pharfet of vitality. Make it a hero ability, and then make it have as many levels as you want.

#3: Not to clear, I can't really understand.

#4: I belive there is already a ability in the WE where in takes a certain amount of mana, and damages you with it. If you find it, set it to drain 999999 and then it will burn all of his mana, and damage him the same way.

#5: All passive abilities are on at all times, so they can't be activated.

Thanks guys. This has been really helpful.

OK, lemme clearify what I meant by those 2 abilities. I was gonna use Magic defense for 2 different abilities. I thought there would be a conflict using the same ability like that. What I was wondering was under the "Damage Taken" value with the Magic defense ability, does that pertain to all forms of attack or just piercing like defend?

Thanks again, Ill add more if I have any more questions :)

I'm pretty sure it is all forms of attacks, but you might want to test this on your own. Make a crappy test map, add the ability to a hero, and make it so that hero can spawn certain enemies with all the different attacks, and then see if it makes a difference on each attack. I'm pretty sure it won't but just to be on the safe side. This option will take a little time, but it will definatly be worth the knowledge.