Boolean working weirdly?

scope Necromancy initializer Init

globals
    private constant integer SPELL = 'A00J'
    private constant integer HEROID = 'U000'
    private integer Count = 0
    private timer TIMER = CreateTimer()
    private constant real TIMEOUT = 1
    private group Casters = CreateGroup()
    private boolexpr b
    private boolexpr unitcheck
endglobals

private struct data
    implement AutoData
    static data temp
    unit target
    boolean used
    timer t
    
    
method onDestroy takes nothing returns nothing
    
endmethod
endstruct

private function CheckUnits takes nothing returns boolean
    local data d
    set d = d.temp
    return GetOwningPlayer(GetFilterUnit()) == GetOwningPlayer(d.target) and not IsUnitType(GetFilterUnit(),UNIT_TYPE_HERO)
endfunction

private function Check takes nothing returns boolean
    return GetUnitTypeId(GetFilterUnit()) == HEROID
endfunction

private function Conditions takes nothing returns boolean
    return GetLearnedSkill() == SPELL
endfunction

private function Remove takes nothing returns nothing
    local data d = GetTimerData(GetExpiredTimer())
    set Damage[d.target] = Damage[d.target] - 5
    set MaxMana[d.target] = MaxMana[d.target] - 50
    call ReleaseTimer(d.t)
    call BJDebugMsg("released")
    set d.used = false
endfunction

private function DoEffect takes nothing returns nothing
    local unit u = GetEnumUnit()
    local unit t
    local data d = data[u]
    local data c
    set d.temp = d
    call GroupEnumUnitsInRange(ENUM_GROUP,GetUnitX(u),GetUnitY(u),600,unitcheck)
    loop
        set t = FirstOfGroup(ENUM_GROUP)
        exitwhen t == null
        set c = data[t]
        if c == 0 then
            set c = data.create()
            set c.used = false
            set c.target = t
            set c.t = NewTimer()
            set data[t] = d
        endif
        if not c.used then
            set c.used = true
            set Damage[u] = Damage[u] + 5
            set MaxMana[u] = MaxMana[u] + 50
            call BJDebugMsg("adding")
            call SetTimerData(c.t,d)
            call TimerStart(c.t,5,false,function Remove)
        endif
        call GroupRemoveUnit(ENUM_GROUP,t)
    endloop
    set u = null
endfunction

private function Loop takes nothing returns nothing
    call ForGroup(Casters,function DoEffect)
endfunction

private function Actions takes nothing returns nothing
    local unit u = GetTriggerUnit()
    local data d
    if not IsUnitInGroup(u,Casters) then
        set d = data.create()
        set d.target = u
        set data[u] = d
    endif
    if FirstOfGroup(Casters) == null then
        call TimerStart(TIMER,TIMEOUT,true,function Loop)
    endif
    call GroupAddUnit(Casters,d.target)
    set u = null
endfunction

//===========================================================================
private function Init takes nothing returns nothing
    local trigger t = CreateTrigger()
    call TriggerRegisterAnyUnitEventBJ(t,EVENT_PLAYER_HERO_SKILL)
    call TriggerAddCondition(t,Condition(function Conditions))
    call TriggerAddAction(t,function Actions )
    set b = Filter(function Check)
    set unitcheck = Filter(function CheckUnits)
endfunction
endscope

  if not c.used then
            set c.used = true
            set Damage[u] = Damage[u] + 5
            set MaxMana[u] = MaxMana[u] + 50
            call BJDebugMsg("adding")
            call SetTimerData(c.t,d)
            call TimerStart(c.t,5,false,function Remove)
        endif

if c == 0 then
            set c = data.create()
            set c.used = false
            set c.target = t
            set c.t = NewTimer()
            set data[t] = d
        endif