(Weak Auras 2) Modifying a custom aura

[Empulsiv3]

So i have been trying to experiment with some auras i have found and i really wanted to adapt what Theck made in his prot pallly auras to my ret auras.
One in particular was his sacred shield one that when 10 seconds remaining on shield buff to the player the weakaura would show up and bounce

Custom trigger
function()
local name,_,_,_,_,_,expires,caster = UnitBuff("player", "Sacred Shield")
if name and (expires - GetTime()) > 10 then
if caster == 'player' then
return false
end
end
return true
end

Custom Untrigger
function()
local name,_,_,_,_,_,expires,caster = UnitBuff("player", "Sacred Shield")
if name and (expires - GetTime()) > 10 then
if caster == 'player' then
return true
end
end
return false
end

What i am looking to try and do is make this aura for a spell cooldown namely Seraphim so when the cooldown of Seraphim reaches 5 seconds remaining it would do the same thing and show up and bounce up and down.

any help with this would be much appreciated

[Translit]

so change Sacred Shield to Seraphim and 10 to 5?