Okay i have some ideas...
Ninja:
Smoke Bomb: [Triggered]
The ninja throws a smoke bomb on the ground wich causes all units inside the smoke to miss some of their attacks and allows the ninja to sneak away in the confusion.
Base spell is Wind Walk. Set movement speed bonus to 0 or less(ex: -50%).
Dummy spell is cloud. Change it so it won't only (or not at all) targets buildings.
Trigger: Create a dummy unit, add the spell to the dummy unit, set the level of cloud to level of Smoke Bomb, order dummy unit to cast cloud at position of casting unit, remove dummy unit. Simple huh?
Kage Bunshin (Shadow Clone): The ninja creates an illusion of a target unit wich deals x% of the targets base damage and takes y% more.
Base spell: Wand of illusion. Just make it a hero ability and add levels.
Combat Skills: The ninja is adept at avoiding damage and dealing critical blows to the enemy. Gives a x% chance to do y times his damage and z% chance to avoid an attack.
Base spell: Drunken Brawler.
Kawarimi no Jutsu (Replacement techniqe)
May be triggered) The ninja traps the enemy in an illusion so that he thinks he is fighting the enemy when it really is a log.
Base Spell: Reincarnation. Change the effect to a log instead of that cross.
If triggered, just base the ability on bash and remove the percent chance. Then make a trigger:
Events:
+A unit is attacked.
Conditions:
+Level of Kawarimi no Jutsu for Attacked unit is greater than 0.
+Random number between 1 and 100 is less than or equal to x(x= percent chance. U decide how much it will be)
Actions:
+Create a Log(Like a dummy unit but with a model like the doodad log and collision size and such. BUT no movement speed or attack.
+Add a 5 seconds generic expiration timer to Last created unit.
+Move Attacked unit to (This is point with polar offset) position of Attacked unit towards 100 and angle Facing angle of Attacked unit.
And that should be it! For the ultimate i would chose the triggered one, since it will look more like a Kawarimi no Jutsu, but it's up to u
Alien:
Face Hugger
May be triggered) The Alien lays an egg wich will be hatched in 5 seconds. If not destroyed before that, a face hugger will spawn. If the face hugger kills a unit another face hugger will be created.
The only triggered part here is the part with the egg that wont create a unit if it is destroyed before 5 seconds. I'll explain: Base Spell: Feral Spirit. It creates a unit( The Egg). This unit has a spell that is based on spawn hydra(change it so it creates one face hugger, or so it lays one more per level the spell is.) When the egg dies it will create a face hugger. The face hugger shall have the ability parasite, wich is autocast when created and adds the parasite effect to the face huggers attack. Now all you have to do is to change the unit so that it spawns a face hugger( obs it shall be the same unit as the one coming out of the egg, since they shall be pretty easy to kill, but is able to create a army of face huggers.) and not a murloc
I don't have time to tip u about more spells now, but i'll come back!