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Note that my rating will not have any influence to moderators reviews.
This review consists out of my personal attidude and opinion about this spell/these spells.

Review

Idea/Creativity: 6/10
Coding: 8/10
Balance: 8/10
Ability Tooltip: 10/10
MUI: Yes (+2/10)
(Yes: +2/10, No: -2/10, MPI: +/-0/10)
Language: Jass (+1/10)
(GUI: +/- 0/10, Jass: +1/10, vJass: +2/10)
Total: 35/40

Medial: 8/10 = 4/5

Viewers Note:
Ahh...good old Jass spells .. ^^ The spell Broken Phantasm is pretty neat, the Mamaragan is rather simple but OK.
Your coding seems to be OK except of some flaws.

1.

JASS:

local location loc=GetUnitLoc(target)

Locations shouldn't be used. As I can see correnctly, you don't even use it. So better delete it ^^
2.
Get rid of the TriggerSleepActions.
3.

JASS:

    local unit dum1
    local unit dum2
    local unit dum3

A unit array would save lines and make it look better. So you can also use a loop.

It is balanced well, though I recommend to define the damage in a seperate function to make it easier configurable. Documentation is well made except of telling about rawcodes.
No need to tell much about the ability tooltip, it is just perfect.
MUI and Jass -> extra score.

All in all neat (good old Jass) Spells, recommendable. Fix the things I mentioned and it would be even better.