--Custom Trigger
function()

    local name, rank, icon, castTime, minRange, maxRange, SpellID = GetSpellInfo(11366)
    local _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, duration, expirationTime = UnitBuff("player", 209455)

    local PyroCastTime = (castTime/1000)
    local BuffLeft = expirationTime or 0 - GetTime()
    if PyroCastTime < BuffLeft then
        return true
    else
        return false
    end
end

--Custom Untrigger
function()

    local name, rank, icon, castTime, minRange, maxRange, SpellID = GetSpellInfo(11366)
    local _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, duration, expirationTime = UnitBuff("player", 209455)

    local PyroCastTime = (castTime/1000)
    local BuffLeft = expirationTime or 0 - GetTime()
    if PyroCastTime > BuffLeft then
        return true
    else
        return false
    end
end