Note, this is for the first meeting in Cenote, not in Xibalba. I didn't know there were two until I googled Skurkis.
So I've finally broken free from the quick and easy fun of killing Loremaster a gazillion times with only a couple spells to show for it (only that life spider for Alexander, and my theurgist now has two spells, neither of which are life)... and finally started to quest again.
As can be expected, the creatures in Azteca are hitting fairly hard. They have added spell penetration and score more criticals than in Avalon. As I started questing in Cenote, the easiest thing for me to do was construct a deck that loaded with Empowerment/Meteor Strike/Colossal. I would clear the field in around 4 turns, 2 if I were extremely lucky (scoring at least one critical that they don't block).
The bosses in this area range from 13000 health to just under 20000 (so far). I was forced to tinker with a deck to get the right set up to beat Skurkis Screaming Moon. She can heal back up pretty fast, and she is going to dish a lot of damage that will be hard to soak up if you solo. She has a Moon Skull Zombie helper with 3000 health, and she has just under 14000 herself. I toyed with sending lots of Efreet to keep her attacks small, but I wasn't able to generate enough mana pips to constantly send them her way. Thus I was forced to load up Death Shields in my treasure card slot.
My equipment is geared for accuracy, so I don't fizzle often, but it's at the expense of critical and power pip chance. Also, Skurkis was overcoming my critical block more times than was comfortable for me. I needed to go first this battle, and I needed to drop the zombie helper quick.
I used an Armillary Deck with these cards stocked:
3 Fire Trap
1 Elemental Blade
1 Elemental Trap
11 Death Shield treasure cards
I also have these Item Cards from my gear:
1 Fire Trap
Besides hitting hard and healing back up with Scarecrow, Wraith, and Satyr (it says she's equipped with a life amulet, so she has the Satyr and the heal charm too), Skurkis likes to drop 30% weakness spells on you. You will need to decide if you want to just add more traps and blades to overcome them or save your wand shots to get rid of them.
The way I worked the fight was dropping Empowerment often to get extra pips. Each time I put a Colossal on an Efreet, I would use the extra card slot to draw a treasure card, which would be a Death Shield. She does have a Skeletal Dragon, so be careful not to have more than one shield up at a time, or she may cast that and eat through your shields too quick.
To kill the Zombie, I used one Colossal Efreet after I was bladed. It was enough to outright kill it.
Then the trick was to just keep dropping traps and blades while keeping a shield up as often as I could. It sounds so easy, but I had only around 500 life left at the end of the battle. I made sure to get my Backdraft up to full pips before casting (it wound up being a 10 pip spell, as I wasn't generating many power pips that battle). I dropped every trap and blade I had on her, except Wyldfire. I was a bit risky in the end... Instead of waiting one turn, drawing a Death Shield and laying it down, I was impatient and cast the Efreet. Only a 6 percent chance of fizzling while she had 6 pips on her end...
It wound up being overkill, even without dropping the Wyldfire. It was 30000 damage spell once everything was tallied. I found this strategy to be best, as I didn't have to worry about whatever health she was siphoning off me or if she would try and heal up... one shot would take care of it, rather than trying to compete with her life gaining. But I would have gone nowhere without the shields. I wound up using all but 3 of my treasure cards.