Input the following seed into the Community Challenges section.
Start with the Handheld Totem champion and the Cutglebeard artifact. For now the strategy is to simply stack conductors in front of the champion.
Take the Restoration Detonation card from the first fight then take the right path, picking up Coldcaelia and slapping multistrike on her at the Merchant of Steel.
Grab the Ice Tornado from the second fight and again go down the right side. Add the Titan Sentry to your deck them reroll the Merchant of Steel to put Largestone on it. The strategy from here is to put the Titan Sentry on the first floor and the champion/Coldcaelia/construct combo on the second.
Pick up the Lodestone Totem from Daedalus and increase your capacity. You can start adding the Totem to the floor with the Titan Sentry to reduce the damage it needs to absorb. Make sure you cast your spells on this floor but just so that the enemies have 1 or 2 attack left. You still want them to his your Sentry and stack Frost.
Take the right path after the boss and grab just the 75 hold. Choose the Handheld Totem II upgrade for your champion.
On the 5th level hang a left and reroll to trinket shop to get the Titan's Claw and start purging those conductors.
On the 6th level go right and hit the Ice Cave. Put the option to reduce a monster to 1 capacity on your Titan Sentry. Now all of you non-conductor monster should fit on a single floor.
After the Aechus fight take the ember upgrade then hang a left to get rid of a couple more conductors and use the Merchant of Steel to add another multistrike to Coldcaelia. This time take the Chillwind champion upgrade.
I suggest taking the trial on level 7 for the extra 400 gold. This will be useful for paying to purge some final cards before Seraph. Take the left path after the fight and reduce a couple of your spells to 0 cast and add 10 magic power to your Restoration Detonation with a reroll. Purge yourself down to around 18-20 cards (dropping lances and restores) and you're good to go. Make sure you keep your Razorshar Edges to put on Coldcaelia and your champion to counteract Seraphs sap he puts on them.
The boss fight is pretty straight forward. I put everyone on the second floor to ensure I got the setup I wanted then cast my spells, keeping an eye on Coldcaelia and the champions attack. Save your permafrost spells for the final fight with Seraph if possible but it's not a big deal if you need to use them early as they aren't consumed on use.
This can unlock the Win at Covenant 5, 10, 15 and 25 achievements if you do not have them already as well as The Stygian Guard.