[p3lim]

Alright, haven't really used animationgroups before so I just found it weird to be used like this.

One thing tho, to avoid spamming the loading process, run :Play() on PLAYER_LOGIN.

local function Update(frame)
    -- do whatever
end
 
local index = 1
 
local handler = CreateFrame('Frame')
handler:RegisterEvent('PLAYER_LOGOUT')
handler:RegisterEvent('PLAYER_LOGIN')
 
local animation = handler:CreateAnimationGroup()
animation:CreateAnimation():SetDuration(1/3)
animation:SetLooping('REPEAT')
animation:SetScript('OnLoop', function()
    if(t9e5e5rb and _G['NamePlate' .. t9e5e5rb]) then
        index = t9e5e5rb
        t9e5e5rb = nil
    end
 
    while(_G['NamePlate' .. index]) do
        local frame = _G['NamePlate' .. index]
        frame:HookScript('OnShow', Update)
        Update(frame)
 
        index = index + 1
    end
end)
 
handler:SetScript('OnEvent', function(self, event)
    if(event == 'PLAYER_LOGIN') then
        animation:Play()
    else
        t9e5e5rb = index
    end
end)