Yeah the strongbox thing was a troll lol!
What flasks do you have equipped?
Edit: If Harbinger ends, my character gets transferred to Standard League, right?
Yeah character gets transferred to Standard.
My flasks are Atziri Promise, Taste of Hate, Lion's Roar which are unique flasks, then a Jade Flask and finally a Stibnite flask.
I am scaling Physical damage for this build and converting all to cold.
Atziri Promise scales both my physical and Elemental and gives me extra chaos damage from it. It's also some very much needed chaos resistance on the character. This flask costs only 1-2 Chaos, everyone has one of these in the mid to late game.
Taste of Hate converts some of my physical damage into extra cold damage which means it's the best flask for my build as I am scaling both. Further more it converts incoming damage into cold which is them mitigated through my cold resistances, essentially making me tankier. Finally, this flask raises my maximum cold resistance by 5% which means I take less damage from cold damage on reflect enemies. The chill/Freeze avoidance is irrelevant for my build as I am always Freeze immune thanks to Raider ascendancy. This is a very expensive flasks cost me 120C.
Lions Roar boosts my physical damage by a lot which gives me more damage. It also adds knockback to my attacks and gives me some needed armor. Another great flask for this build. This costs 7-8 fairly cheap for the power it gives.
Jade Flask gives a ton of flat Evasion which is what this character is stacking for damage through Dreamfeathers and movement speed through Queen of the Forest chest. It's also a must for this build and makes you untouchable against mobs. I have bleed removal on this flask. I crafted this flask myself.
Stibnite Flask creates a smoke which blinds enemies which makes it even harder for them to hit me. It also increases my evasion by 100% meaning when I use Jade plus Stibnite my Evasion is through the roof like 50k+ so these two together act like Quicksilver/Onslaught flasks plus nice defense from evasion. I have curse removal on this because you want Curse removal all the time up when mapping late game and Stibnite has a lot of charges making it the perfect flask for this. I crafted this myself too.