Intro

Father Mateos stats aren't really amazing for Hard-(core)-mode, a 4323 Statline normally leave him quite badly on Chain, but his -Token-Ability and this Deck can help him get better numbers. :-)
The main tactic in this deck is to disable the Chaos Tokens with the capability to Seal a amount of Cards and reveal as many Tokens as possible to draw the -Token and get a Extra Action

Upgrades (listed in priority) (To make a legal Campaign starter)

Spell

• Seal of the Elder Sign (5) from Defiance don't no what to put else, but you need the Card for his (-)ability
• Shards of the Void (3) from Wither: Wither is better then Shrivelling, because you while draw allot of special Tokens
• Sixth Sense from Sixth Sense (4) yeah, what?
• Deny Existence from Deny Existence (5) helps with encounter handling

Other

• Crystalline Elder Sign (3) from St. Hubert's Key the boooooooost is better and the seal is negible after the Kodex. (The plus one even highers the chance for the )
• Eucatastrophe (3) from #Noidea: you need the for this deck
• Jewel of Aureolus (3) from Holy Rosary
  (the key and the rosary give a good boost for the first scenario)
• Relic Hunter (3) allows both Crystalline Elder Sign (3) and Jewel of Aureolus (3) to be in play at the same time
• Recall the Future (2) from Arcane Studies
• Emergency Cache and Fearless: are just downgraded

Detailed Ploting

0 MULLIGAN
Keep:
Eucatastrophe (3) or Seal of the Elder Sign (5)
1x or 2x Spells
Crystalline Elder Sign (3)

0 -Ability
So. His -Ability gives him a Upkeep-Phase or own action. The goal is to you this ability as most as possible with Eucatastrophe (3) and Seal of the Elder Sign (5) you can youse this up to four times and with The Codex of Ages also 1 time. Note that Dark Prophecy also can pick out the -Token that means you can activate his with it.
That means you can get the -Ability 6 times without the normal tests, Eucatastrophe (3) and his ability paired (or not) with Dark Prophecy can even be yoused after the Token was revelead. Even with Olive McBrides weak point looses its difficulty because the -Ability gives you a automatic success. And the best thing is that you can do all this while you preform other normal actions. And then if you finally reveal the token you

1. Automatically succeed and,
2. can take a action or do a Upkeep Phase (whatever brings you the most profit in the situation).

0 Chaos Bag Handling
The goal is to draw as many Tokens as possible to get Bonus with Ritual Candles and Jewel of Aureolus (3). The Olive McBride and Dark Prophecy combo allow you to hopefully draw a , , or token, while a skill test (When his -Ability was not yoused yet even the token). You can use Recall the Future (2) if 1 of the Tokens would make you fail the test.
Olive McBride should be in your Zone asap, and with the 3 Token draw you should get the +1 from the Ritual Candles. Then you have Crystalline Elder Sign (3) to give you a +1, and then Recall the Future (2) and Arcane Studies can give you a boost till +2-+4. THEN the Spells give you a +2 boost.
At the end you will have a boost of +6-+8 boost what should be enough for the Chaos Tokens in the Hard-Mode.

0 EXP.
The hole deck costs 69 Exp. A good scenario resolution gives you ci. 4-6 Exp., +2 per resolution with Delve Too Deep and a other +2 on Spells with Arcane Research. All of that give you with 7 resolutions a 36-54 Exp. So if you don't get all the stuff just let it (like Fearless (2), Emergency Cache (2) and Deny Existence (5))

0 Yig
At last I want to talk about the Weakness in this Deck, the Serpents of Yig. When it comes in play it seals the -Token, but this token should either be sealed on The Codex of Ages or Crystalline Elder Sign (3) and Seal of the Elder Sign (5)/Eucatastrophe (3) read: "... treat it as " (that also helps when its sealed on a other card). So it is not the highest priority to kill the Serpent (when you can't leave your location just youse Wither).

Thanks for reading and hope you don't draw more than 1 !