Dawn Office Sinclair Solo (ft. House of Sacs)

Your final floor should be an easy one, these are the easiest imo.

Unhatched Embers IS A MAIN PRIORITY. It's an incredible revive option.
Mid-range K Corp. Ampule is another solid revive option.
Contempt of the Gaze of Contempt is more damage and negligible HP & SP damage basically.
Pick them before F13 because waves are horrible after you get the shield adversity.

Red Necktie synergizes really well with Blazing Strike

This solo is all about making use of [Sinclair] Dawn Office Fixer's massive buffs when both Dawn Office members die, which are Loneliness at High Noon and
Blazing Sunset respectively. Through the use of Spiderweb Entangled in Red, we can keep both of them dead for as long as needed, which is why [Ryōshū] Blade of the House of Spiders is mandatory too to maintain the anti-revive portion of the gift. We can put HoS IDs on everyone else and let Ryoshu kill them (giving us a level's worth of Offense/Defense Level per sac) or just have relevant support passives.
Pros:

• Sunset Blade is an amazing wave clear option and sets an incredible amount of Count even without MD or Dawn buffs.
• Blazing Strike gets massively buffed thanks to Scorchfield and Dawnherald. It being a Wrath skill helps trigger For the Capo and other good gifts.
• Faust increases his base power, damage and burn proc and gives him an anti-death/stagger once per Encounter.
• Gregor solves all SP issues Sinclair has, gives him an HP-scaling shield every turn and a stagger removal.
• Having access to Tremor thanks to Wing-shaped Waxen Candle is pretty neat as it has lots of good gifts.
• Aura.

Cons:

• Fierce Charge is only useful if you have Grey Coat for sustain.
• We are forced to put Blade Ryoshu on the Loadout because of Spiderweb Entangled in Red to keep the Dawn members dead.
• We cannot get Torn-out Butterfly from her gift even if we kill the rest of the sinners because Ryoshu will keep reviving.
• No Tremor Burst nor Count from Sinclair :(
• SP Fatigue II actively kneecaps him so much it's not even funny. His passive loses 1 or 2 Coin Power and his Sunset Blade loses attack weight. This is why the on-death buffs are so important for 60ADV to even be possible.
• This has so much setup that the solo moniker can be misleading.

UPDATE: Changed around the floor 1 because I completely forgot about Baba Yaga. This makes the solo significantly easier to setup, thanks to the one that mentioned it :p

• Ashen Constellation's Blessing is TOP PRIORITY. It removes damage type weaknesses and gives free Protection.
• Spent Use, Forming Hate is 1 free Attack Power Up, so it's good.
• The Unchosen gives more Sinking to enemies, which is decent.

The rest of Walpurgisnacht packs aren't that interesting for this character, so we are on Infinity mirror packs already.
You can change this for any other Bokgak pack and get it later if the clear rewards are better.

• Huge Gift Sack is the main one here. 2 Protection for free is great.
• Sad Plushie is the most important keywordless one. Get this pack ASAP if you see it on rewards and aim for the fusion.

The rest EGO gifts are fine, but not mandatory.

MANDATORY PACK:

• Wing-shaped Waxen Candle is the main reason why we are picking this. It makes Sinclair count as a Tremor unit and gives Dawnherald for the first turns. Reset if you don't get this.
• Searing Brass increases Burn Potency cap, adds Wrath damage to burn procs and gives a whopping +30% damage increase.
• Entangled Fate will take a while to matter until you get 7 skill slots. Not that important outside really long fights.

If you don't care about Entangled Fate, Season of the Flame is another option to get the other two.

Self-explanatory burn upscale pack. Get the Burn gifts for increased Count, Potency and other buffs.
Modified Extraction : AEDD gives us Offense Level Up if we have Charge gain gifts.

Generic Tremor upscale gifts.

• Emergency Investigator Badge is the most important gift, as it's a revive option
• Chalice of Trickle-down is a great Clash Power boost
• The rest are good to have, not much to say

Get immediately if Bridle is a clear reward. It jacks up your HP, and Blazing Sunset's Shield by extension.

Snake Slough is a solid Defense Level Up buff that makes it give you Offense Level Up as well.
False Halo makes your damage increase over the course of a fight.

Burning Fate increases Burn Potency cap and gives Offense Level Up on skill use.
For the Capo is good after Turn 4 if you use 4 Blazing Strike in a row.