In Rune Slayer, you will find 10 main bosses that spawn at different locations, and you must defeat them all to progress in the storyline.
All these available bosses only spawn when you reach their respective locations, so to face the enemy, you must enter its area.
Slime King, Goblin Champion, Mandrake King, and Rat King are a few of the main bosses that you will encounter.
Location Of Rat King In Rune Slayer
The way to the Rat King traverses through dangerous lands, beginning southwest with the wilderness.
After some time, you will come across a very distinctive wall across the terrain. Moving along this wall downward, one should come across a cave entrance to the inner domain. Keep your eyes peeled for aggressive frogs that call this zone home.

Once inside the cave, the first thing to note is a specific patch of moss. This little growth serves an important purpose: it is the very entrance to the Rat King’s territory.
By interacting with the moss, one discovers a secret passage that leads right into the chamber of this fearsome foe.
The Fight Against The Rat King
It takes a second to get killed if you walk in unprepared to fight that Rat King. Preparation and resources are the essence of accomplishing this feat.
The merchant nearby the apple pie vendor sells Antidote Potions, which you must have to win the fight.
While solo victories for the experienced adventurer around level 20 may be possible, a balanced team gives you a better chance for actual success.

The Rat King’s fighting style is a mix of brutal physical attacks and remarkably deadly poison techniques.
It has powerful multi-hot combinations strong enough to break your block, followed by that ludicrous lunge that is a parry test.
However, the most threatening attack is when it fills the entire chamber with poisonous gases; however, proficient Strikers can thwart this attack with Rapid Strikes.
The battle is like a deadly dance, with the Rat King always forcing you to change your plan. You can avoid most of its attacks, but to try and parry the Rat King’s multi-hit combos is a death wish.

If an antidote potion is used at exactly the right time, the odds of victory would be stacked in favor of victory.
This precious consumable negates the poison effect and allows the team to remain alive for even more precious moments during a long fight.
So, by teaming up with your friends and using the right amount of potions, you will be able to defeat the Rat King in his cave.