Formation 4 is good too. Formations 1 and 2 are very niche
Fast slash is extremely good for certain stuff, including content you have not unlocked.
Conqueror resetting from space fights is annoying, but doesnt slow you down that much.
The level xp requirement reduction based on rebirth points is not that useful till much later too.
Formation 2 is the only good one, double damage.
Formation 1 gets you hardstuck in a regen loop battle and Formation 3 is like Formation 1 but worse
Formation 4 would be ok in theory, but guess what. The more you progress the better loot you get. Maybe if your damage was halved Formation 4 would scale better than just progressing further - but it doesn't, it cuts your damage to a quarter, and it simply doesn't give you enough bonus to be worth that. Damage is so important in every metric.
Content I haven't unlocked? As far as i'm away there's very minimal things I haven't reached and it's *just* a bad damage buff, you don't actually swing faster you attack slower and it doesn't stack over to the next enemy, meaning you farm slower, clear bosses slower, there is no net positive to it
Conquerer slows you down so much - both the attack and damage buffs, 20 minutes to reset, and if you're at a stage where you need those buffs to clear areas quickly then it will cripple you- it doesn't slow you down if you get rid of it, but if you're trying to use it then it most certainly does
Level xp reduction is very helpful by the time corruption even starts- have you actually played? When the comment was left the 'level xp reduction' was effectively disabled, making it much much harder to infinity at all.
You get way more XP alone one shotting enemies 6 stages earlier from formation 4.
Fast slash is really good for taking out space enemies. Level 1 is literally do two attacks each time you attack with a downside that is worse the lower your attack speed is. The worst part is just getting it to level 3. I usually only got it to level 2 early on. Then there is also a point where you get your attack speed so high, that the flat attack speed debuff from fast slash is negligible and you farm a faster with it too, due to enemies being able to have the dodge curse.
Another tip is you can cheese space bosses with level 3 extra life and level 2 berserk. The synergy is incredible.
