How would you make this spell?

How would you make this spell?

Sacrifice
Target one of your own units and then one of your enemies to automatically kill both of them. Units may not have more than 600 HP difference.
Level 1: 90 mana, kills 1 enemy unit
Level 2: 80 mana, kills 1 enemy unit and damages a random enemy unit to half health within 600 range
Level 3: 70 mana, kills 1 enemy unit and damages 2 random enemy units to half health within 600 range.

or is this spell even possible?

1) I know of no existing spell that has double targetting.
2) I doubt that you can use triggers to force a second targetting on the user.

may not have double targetting but maybe can make an area spell and do a trigger which picks a enemy unit and a friendly units and do actions else do nothing. or something like that... i tink

For the second targeting, add a dummy ability and use Player - Force UI Key to target it. The ability must have a hotkey. If you need an example of this, tell me and I will e-mail you one of the previous versions of my Point-to-Point Portal spell.

~The_Raven