After you beat the Executioner, you proceed to the throne. The king greets you and explains that your witch mother wasn't really kidnapped. The king called for her because he has a major problem in the catacombs: Someone or something is raising the dead, and she's the only one who can stop it.
You can choose to peacefully enter the dungeon and find your way to the catacombs. Or you can attack the king. If you defeat him and his guards, you can take the Royal Scepter, which enables you do summon castle guards to aid you.
Beside the scepter, a bunch of new weapons are added to the game: the Shepherd Staff turns enemies into sheep, the Turret Staff creates standalone copy of the staff that autonomously shoots at the enemies and the Earthquake Staff knocks down all the enemies and destroys some rocks. The stronger your Magic skill, the more rocks will be broken. For combat, Earthquake Staff is a melee weapon - you can strike or knock down enemies, similar to Warbreaker Hammer. The Earthquake Staff is currently the only weapon that scales both with magic and melee skill. This means that you can upgrade it with both Warlock and Blacksmith runestones.
Beside all this, two new room types have been added. First one is the Scroll shop, which sometimes shows up as an alternative to the Potion Shop. The shop offers all four types of scrolls for that run at a low price, and you can buy an identify scroll for only 10 gold coins. The second one is a special room in the castle where the Ogre Mama is fighting the castle guards. It can only show up if the Ogre Mama boss is absent from the forest.
Additionally, the Fireball Staff now adds 1-battle fire immunity to the caster who activates the fireball buff.
The new version also contains one very important bug fix: the hitbox for the sword strike of the Guard Captain was wrong on the first strike, so she could sometimes hit targets that are far away from her. This is fixed in version 1.8.6.