I league start it and got 100m last league (Sentinel boots won't exist though). I didn't use the Iron Fortress Chest, but I was one of like 2-3 people out of 25ish that didn't. Iron Fortress is just very easy omega dps and some decent defense so it'd definitely be hard to replace without a god-tier rare or close to it. For example:
is what I made and it honestly cost maybe 10ex to make and I did it the dumb way. Elder can roll %strength and %crit. This looks less than the Iron Will/Crown of Eyes/Fortress combo but the extra curse and the raw crit helps me out where I don't need power charges like most people do with their stupid mines to reach 100% crit. Also allows me to stack more multi elsewhere.
There's actually a LOT of interesting shit to be done. Frostblink, Frostblink/Flame Dash totems, SHIELD CHARGE, and even Cyclone. Conc path doesn't get any big bonuses for +levels like and unfortunately neither does Flicker Strike.
Cyclone will get a NICE amount of QoL if you hit 8 stages on that motherfucker with a +1 neck and if you use an Ashes (lol) you can get omega area for zoomin'. Depending what they give Trickster, the movement class, we could be in Legion League territory of a million billion Cycloners again. Could be good, it's been a while where Cyclone was more than a CoC mechanic.
Frostblink scales INSANELY with level and there's a lot of ways to add even more levels until you get something nutty like a lvl 36 Frostblink which will just absolutely TRUCK. Mathil did a Frostblink totem build before buffs 2-3 leagues ago and the clear was mediocre, but it was a boss destroyer if you could keep the target on screen. People also say cold to fire ignite Frostblink is very good and I probably believe them. It has one of the best raw +level scaling of any skills in the game.
Shield Charge gets great bonuses (+raw, +flat per armor/es) at skill thresholds so you could see some Facebreaker/Shield Charge shenanigans for sure. There's about a 75% chance Facebreakers are getting buffed too, so in my mind there's going to be about 20+ viable red map clearing builds where offense is decidedly done and you can work in defenses with your effort to make it an all-arounder. Maybe not boss blasters, but people are going to definitely be able to fuck around if these Uniques keep coming out with ACTUAL buffs rather than 15% damage/defense mark-ups.