Pharoah Guard

[mancco]

Doubles the users Defense and Special Defense, but halves Attack and Special Attack.

This could be a hidden ability for Cofagrigus

[blackburn009]

That sounds terrifying, without investments cofagrigus would have more SpD and Defense as shuckle if it had 252+ in each of its defenses

[Leafeon]

Too overpowered. I mean cofag is supposed to be a switch in and willowisp to cripple attackers Now it can take hits better than lugia,set up toxic spikes,remove your item,and possibly set up trick room! Cofag doesnt really need its attack and SPatk too much anyway (all it uses its attack for is knock off). but i recommend just 1.5 def or spedef. Cofag also has access to pain split which is amazing at recovery and lefties will also help it out in that department as well.
Just to show the brokenness 
Max Def+ cofag: 427x2=854
Max spd+ cofag: 339x2= 678
Sorry manco but you borked the defense levels. If I were to change it I would change it so that you start at 50% or Debuff the Defence to 1.25 on a stat

[Alphajores]

Not to mention that Cofagrigus already has a signature ability

[Devoxys]

OP. I think you should nerf the defense/spD increase to about 1.25x, maybe even a bit more.

[Cyberknight98]

Yeah, I could maybe see it with a different name as a mega evo ability, but only for pokemon that already don't have high defenses

[Galom]

Utterly broken ability. Not happening. Needs substantial work to even be considerable. However, Cofagrigus has kinda shown that it's always going to have one ability. If it was ever going to get a Hidden Ability, it would have in Gen V. It's a lot like Zoroark.

[Cyberknight98]

Hydreigon's HA is best HA

[Deleted]

Could be something like Fur Coat but only for SpD.

[Snaquaza]

This is uh.. overpowered, I may consider it if does something much less good, but Rejected 1/2 for now.

[Galom]

Rejected 2/2.