Lighthouse shaped map and Diviners chest

there seems to be a lot of weird balance issues that remain inside Betrayal. One of which is lighthouse shaped map. The boss at the end of the map is overpowered it seems, my character has 8k hp 80 fire, cold, lighning res, and 22 chaos res atm and 65% phys damage reduction as I am a juggernaut. He also has dual wield weapons(fate of the vaal and the axe that gives infinite attacks despite no mana), and his damage says 200,000 to 250,000. although the bosses are killed really fast with how much damage and penetration my hero has, one of the bosses will come in out of no where while im killing oe of the othrs and do some sort of magma orb attack that instantaneously kills me with 1 hit, not even a crit, also the map mods will be very mediocre and result in the same. The second insane imbalance I notie is the diviners chests, ive used around 1,000 chaos over 20 diviners chest and got a variance of unique items and corrupted itens or currency cards with 45% extra quantity and chest level 5 and every single time I now only get chaos cards or really cheap ones, no more kings heart cards or the wolf, or even boon of the first ones, which are mediocre compared to other amazing cards you used to get. Why are the diviners cards coming out of the chests you spend 100 chaos on rerolling only spitting out 2 to 5 chaos cards now?