Lets be real... the boss fight is awful... it's the most "You're not allowed to play" fight in the entire game
You can't use bombs if their range is too short because it deletes anything close to it and also just randomly deletes them when placed anywhere in the boss room.
You can't use swords because it's surrounded by several high HP infinitely respawning tentacles.
You can't use the vast majority of guns because again it infinitely spawns tentacles to block any bullet.
The only things you're allowed to use are weapons with piercing projectiles... this means.... the charge attacks of Brandish, Sealed sword, Antigua, Tundrus, and Magnus weapons.
As if this wasn't bad enough it also is in a room with infinitely respawning glop drops, and it's main attack is an AOE that is such wide range and speed that even IF you see it coming you can't move out of the way if you're trying to use a Sword charge attack.
To make matters worse it can spawn in ANY Stratum.... how is this supposed to be a fun experience for new players? Even for intermediate players? Right now there's one of these levels at depth 3... I challenge any dev to try and beat this with 0 and 1 star gear... If this boss can't be beaten by the players you're presenting this to then it's a bad design.
Worse still.... what's the reward? You get nothing special for beating it... a few Slime coins that are only usable during certain events and can be acquired from ANY slime monster... even the payout isn't that good in terms of CR.... and even for those who fight the Tier 3 one there's an extremely small chance to get an extremely rare trinket with an absolutely useless effect.
This "Boss" needs a heavy makeover and total rework of mechanics... and until it gets updated, it shouldn't be allowed in the lower levels of the Arcade.
The trinket needs a serious rework considering how difficult it is to obtain.