[Niketa]

The code I currently have is all over the place and will give you a headache. It's currently functional in my test environment (have not been able to test all bosses yet since I don't lead my raids until the weekend) but I'm starting over from scratch to try do it right.

This is what I have so far. Obviously it's not done, but this is the new direction I'm heading based on the feedback you guys have given.

local bossNPCID = {
    [55294] = true, -- Ultraxion
    
    -- Madness of Deathwing... check combat log next time to see if there's any NPC that shows up regardless of what platform we start at.--
    [56846] = true, -- Madness of Deathwing: Arm Tentacle
    [56167] = true, -- Madness of Deathwing: Arm Tentacle
    [56168] = true, -- Madness of Deathwing: Wing Tentacle (Need to check if there's a second NPCID during raid, only one listed on WoWhead.)
    [56173] = true, -- Madness of Deathwing: Deathwing
    ----------------------------------------------------------------------------------------------------------------------------------------
    
    [52530] = true, -- Alysrazor
    [52409] = true, -- Ragnaros
    [46753] = true, -- Al'akir
    [33136] = true, -- Yogg-Saron: Guardian of Yogg-Saron
    [60410] = true, -- Elegon
    [36597] = true, -- The Lich King
    [10184] = true, -- Onyxia
    [16152] = true, -- Attumen the Huntsman
    [19622] = true, -- Kael'thas Sunstrider 
    [28859] = true, -- Malygos
    [28860] = true, -- Sartharion
    [69712] = true, -- Ji-Kun
    
    --TEST NPCIDS
    [12129] = true,
    --[[
    [] = true,
    [] = true,
    [] = true,
    [] = true,
    [] = true,
    [] = true,
    [] = true,
    [] = true,
    ]]
}
 
local events = CreateFrame("Frame")
 
events:RegisterEvent("PLAYER_ENTERING_WORLD")
events:RegisterEvent("PARTY_LEADER_CHANGED")
 
events:SetScript("OnEvent",function(self,event,...)
    if event == "PLAYER_ENTERING_WORLD" or event == "PARTY_LEADER_CHANGED" then
        local ininstance, instancetype = IsInInstance("player") -- check if player is in a raid and in an instance
        local isgroupleader = UnitIsGroupLeader("player") -- check if player is raid leader
        
        if ininstance == 1 and instancetype == "raid" and isgroupleader then -- if player is group leader in a raid and currently in an instance enable functionality
            print("|cff00ff00Niketa's Mount Looter enabled!")
            events:RegisterEvent("PLAYER_REGEN_DISABLED")
            events:RegisterEvent("PARTY_LOOT_METHOD_CHANGED") --!!!!!!!!!!!!!!!!!! DON'T FORGET TO DISABLE THIS WHEN REVERTING LOOT SETTINGS!!!!!!!!!!!!!!
        elseif ininstance == 1 and instancetype == "raid" and not isgroupleader then -- if player is in a raid and in instance but not group leader, "error" message
            print("|cff00ff00Niketa's Mount Looter disabled: You need to be raid leader to use this addon.")
        end
    end
    
    if event == "PLAYER_REGEN_DISABLED" then -- on entering combat, start looking at CLEU
        events:RegisterEvent("COMBAT_LOG_EVENT_UNFILTERED")
        
    end
    
    if event == "COMBAT_LOG_EVENT_UNFILTERED" and eventType ~= "SPELL_AURA_APPLIED" then
        local _, _, _, sourceGUID, sourceName, _, _, destGUID, destName, _, _ = ...
        local enemyNPCIDa = tonumber(strsub(sourceGUID, 6, 10), 16)
        local enemyNPCIDb = tonumber(strsub(destGUID, 6, 10), 16)
        
        if bossNPCID[enemyNPCIDa] or bossNPCID[enemyNPCIDb] then -- if enemy is in table then set loot and unregister CLEU
            events:UnregisterEvent("COMBAT_LOG_EVENT_UNFILTERED")
            
            nmlmethod, nmlthreshold = GetLootMethod(), GetLootThreshold()
            
            if nmlmethod == "master" and nmlthreshold ~= 4 then -- only set threshold if already master
                print("no thresh")
                
                SetLootThreshold(4)
            elseif nmlmethod ~= "master" and nmlthreshold == 4 then -- only set method if already epic
                print("no method")
                
                SetLootMethod("master",UnitName("player"))
            elseif nmlmethod ~= "master" and nmlthreshold ~= 4 then -- set both
                print("no thresh or method")
                
                nmlnodead = 1 -- set nil when reverting settings
                nmlsetthreshold = 1 -- trigger PARTY_LOOT_METHOD_CHANGED to set to epic
                
                SetLootMethod("master",UnitName("player"))
         -- else do nothing
            end
        end
    end
    
    if event == "PARTY_LOOT_METHOD_CHANGED" and nmlsetthreshold == 1 then
        nmlsetthreshold = nil
        
        SetLootThreshold(4)
    end
end)

Is this a step in the right direction or am I still way off?

(* I just realized I forgot to add in your suggestion about caching the NPCID so I don't keep calling local enemyNPCID. I don't really understand your code for that [as far as metatables go]; would you mind explaining so I actually understand what I'm writing [we don't want another issue like my local variables for CLEU, lol]? *)