Lua Scripting, Postponing some Events...

[thisisme125]

Okay... I scripted a boss and he uses a spell that casts every 2 seconds. Im just trying to figure out a way to cancel thats specific event to allow other spells/events to be casted/executed without having bugs such as canceling the spell due to another spell needs to be casted.

function Shadow_Shadownova1(pUnit, Event)
	if pUnit:GetHealthPct() <= 50 then
	 pUnit:RemoveEvents();
	 pUnit:SendChatMessage(14, 0 ,"Feel The Power of The Shadow")
	 pUnit:FullCastSpell(38627)
	 pUnit:RegisterEvent("Shadow_Shadowbolt", 2200, 0)
	 pUnit:RegisterEvent("Shadow_Shadowbolt2", 10000, 0)
	 pUnit:RegisterEvent("Shadow_Summon",60000, 0)
	 pUnit:RegisterEvent("Shadow_Spike", 15000, 0)
	 pUnit:RegisterEvent("Shadow_Rain", 45000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowcleave", 35000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowboltv", 20000, 0)
	 pUnit:RegisterEvent("Shadow_Shadownova2", 30000, 0)
	 pUnit:RegisterEvent("Shadow_Crushingshadows", 16000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowburst", 1000, 0)
	end
end

function Shadow_Shadownova2(pUnit, Event)
	pUnit:CastSpellOnTarget(40737, pUnit:GetMainTank())
end

function Shadow_Shadowbolt(pUnit, Event)
	pUnit:FullCastSpellOnTarget(29487, pUnit:GetMainTank())
end

function Shadow_Crushingshadows(pUnit, Event)
	pUnit:CastSpell(40243)
end

function Shadow_Mos(pUnit, Event)
	if pUnit:GetHealthPct() <= 60 then
	 pUnit:RemoveEvents();
	 pUnit:SendChatMessage(14, 0, "You Will Die...")
	 pUnit:FullCastSpellOnTarget(30937, pUnit:GetMainTank())
	 pUnit:RegisterEvent("Shadow_Shadownova1", 1000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowbolt", 2200, 0)
	 pUnit:RegisterEvent("Shadow_Shadowbolt2", 10000, 0)
	 pUnit:RegisterEvent("Shadow_Summon",60000, 0)
	 pUnit:RegisterEvent("Shadow_Spike", 15000, 0)
	 pUnit:RegisterEvent("Shadow_Rain", 45000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowcleave", 35000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowboltv", 20000, 0)
	 pUnit:RegisterEvent("Shadow_Crushingshadows", 12000, 0)
	end
end

function Shadow_Shadowbolt2(pUnit, Event)
	pUnit:FullCastSpellOnTarget(38378, pUnit:GetMainTank())
end

function Shadow_Shadowboltv(pUnit, Event)
	pUnit:CastSpellOnTarget(39175, pUnit:GetMainTank())
end

function Shadow_Shadowburst(pUnit, Event)
	if pUnit:GetHealthPct() <= 40 then
	 pUnit:RemoveEvents();
	 pUnit:FullCastSpell(34360)
	 pUnit:RegisterEvent("Shadow_Shadowbolt", 2200, 0)
	 pUnit:RegisterEvent("Shadow_Shadowbolt2", 10000, 0)
	 pUnit:RegisterEvent("Shadow_Summon",60000, 0)
	 pUnit:RegisterEvent("Shadow_Spike", 15000, 0)
	 pUnit:RegisterEvent("Shadow_Rain", 45000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowcleave", 35000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowboltv", 20000, 0)
	 pUnit:RegisterEvent("Shadow_Shadownova2", 30000, 0)
	 pUnit:RegisterEvent("Shadow_Crushingshadows", 16000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowofdeath", 1000, 0)
	end
end

function Shadow_Shadowcleave(pUnit, Event)
	pUnit:CastSpellOnTarget(30495, pUnit:GetMainTank())
end

function Shadow_Shadowofdeath(pUnit, Event)
	if pUnit:GetHealthPct() <=10 then
	 pUnit:RemoveEvents();
	 pUnit:SendChatMessage(14, 0, "I WILL NOT DIE ALONE!!!!!!")
	 pUnit:FullCastSpellOnTarget(40251, pUnit:GetMainTank())
	 pUnit:RegisterEvent("Shadow_Shadowbolt", 2200, 0)
	 pUnit:RegisterEvent("Shadow_Shadowbolt2", 10000, 0)
	 pUnit:RegisterEvent("Shadow_Summon",60000, 0)
	 pUnit:RegisterEvent("Shadow_Spike", 15000, 0)
	 pUnit:RegisterEvent("Shadow_Rain", 45000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowcleave", 35000, 0)
	 pUnit:RegisterEvent("Shadow_Shadowboltv", 20000, 0)
	 pUnit:RegisterEvent("Shadow_Shadownova2", 30000, 0)
	 pUnit:RegisterEvent("Shadow_Crushingshadows", 16000, 0)
	end
end

function Shadow_Rain(pUnit, Event)
	pUnit:CastSpell(37369)
end

function Shadow_Spike(pUnit, Event)
	pUnit:CastSpellOnTarget(45885, pUnit:GetMainTank())
end

function Shadow_Summon(pUnit, Event)
	pUnit:SendChatMessage(14, 0, "Come, Come and aid me.")
	pUnit:FullCastSpell(33540)
end

function Shadow_OnCombat(Unit, Event)
	Unit:RegisterEvent("Shadow_Shadowbolt", 2000, 0)
	Unit:RegisterEvent("Shadow_Shadowbolt2", 10000, 0)
	Unit:RegisterEvent("Shadow_Summon",60000, 0)
	Unit:RegisterEvent("Shadow_Spike", 15000, 0)
	Unit:RegisterEvent("Shadow_Rain", 45000, 0)
	Unit:RegisterEvent("Shadow_Shadowcleave", 35000, 0)
	Unit:RegisterEvent("Shadow_Shadowboltv", 20000, 0)
	Unit:RegisterEvent("Shadow_Shadownova2", 30000, 0)
	Unit:RegisterEvent("Shadow_Crushingshadows", 16000, 0)
	Unit:RegisterEvent("Shadow_Mos", 1000, 0)
end

function Shadow_Leave(Unit, Event)
	Unit:RemoveEvents();
end

function Shadow_Died(Unit, Event)
	Unit:RemoveEvents();
end

RegisterUnitEvent(85001, 1, "Shadow_OnCombat")
RegisterUnitEvent(85001, 2, "Shadow_Leave")
RegisterUnitEvent(85001, 4, "Shadow_Died")

If you notice in some of the events i was forced to use CastSpell instead of FullCastSpell because the npc will not have enough time to cast that spell.
So if someone can help me out in my problem i'd truely appretiate it.