Header

    globals
        BuffType mOck_AstralRift
        BuffType mOck_AstralRift_Slow
    endglobals
    
    //Do not remove or rename this function!
    //Put your initialization tasks here, this function will be called on map init
    function SPDamage takes Buff b returns nothing
        local Creep c = b.getBuffedUnit()
        local Tower t = b.getCaster()
        call t.doSpellDamage(c,GetUnitMoveSpeed(c.getUnit())*((t.getLevel()*.16)+2),t.calcSpellCritNoBonus())
    endfunction
    
    private function init takes nothing returns nothing
        local Modifier Bmod = Modifier.create()
    
        set mOck_AstralRift_Slow = BuffType.create(2,0,false)
        set mOck_AstralRift = BuffType.createAuraEffectType(false)
        
        call mOck_AstralRift.addPeriodicEvent(EventHandler.SPDamage, 1.00 )
        call Bmod.addModification(MOD_MOVESPEED,-.3,-.01)
        call mOck_AstralRift_Slow.setBuffModifier(Bmod)
        call mOck_AstralRift.setStackingGroup("rift_aura")
        call mOck_AstralRift.setBuffIcon('@@0@@')
        call mOck_AstralRift_Slow.setBuffIcon('@@1@@')
    endfunction

On Damage

function onDamage takes Tower tower returns nothing
    local Creep target = Event.getTarget()
    local Creep creep
    local integer level = tower.getLevel()
    local real facing
    local real newX
    local real newY
    local Iterate it

    if (target.getSize() < SIZE_BOSS or GetRandomInt(0,1) == 1) and tower.subtractMana(30,false) == 30 then
        call Effect.createScaled("Abilities\\Spells\\Undead\\ReplenishMana\\ReplenishManaCaster.mdl", tower.getX()-16, tower.getY()-16, 10, 0, 30).setLifetime(1)
        //Move the creep(s).
        call Effect.createSimple("Abilities\\Spells\\Items\\AIil\\AIilTarget.mdl",target.getX(),target.getY()).destroy()
        set facing = GetUnitFacing(target.getUnit()) - 180
        if tower.calcChance(0.15) then
            //Move all units around the target.
            set it = Iterate.overUnitsInRangeOfUnit(tower, TARGET_CREEPS, target, 175.0 + level)
            loop 
                set creep = it.next()
                exitwhen creep == 0
                set newX = creep.getX() + (175+level) * Cos(facing * bj_DEGTORAD)
                set newY = creep.getY() + (175+level) * Sin(facing * bj_DEGTORAD)
                call creep.moveToPoint(newX,newY,true)
            endloop
        else
            //Move target only.
            set newX = target.getX() + (175+level) * Cos(facing * bj_DEGTORAD)
            set newY = target.getY() + (175+level) * Sin(facing * bj_DEGTORAD)
            call target.moveToPoint(newX,newY,true)
        endif
        //Apply slow
        call Effect.create("Abilities\\Spells\\Other\\Silence\\SilenceAreaBirth.mdl", target.getX(), target.getY(), 50, 0).setLifetime(1)
        set it = Iterate.overUnitsInRangeOfUnit(tower, TARGET_CREEPS, target, 250 + level)
        loop 
            set creep = it.next()
            exitwhen creep == 0
            call mOck_AstralRift_Slow.apply(tower, creep, level)
        endloop
    endif
endfunction

Tower Aura