How to complete Hidden Secrets, Hidden Chambers in Rogue Legacy 2

gamepur.com:

Rogue Legacy 2 can be a tough game, especially when you’re just starting out. Until you’ve given yourself several persistent upgrades, you’re going to have to deal with enemies and bosses that might feel a bit overpowered. Estuary Lamech, the game’s first boss, can be particularly troublesome while you’re still learning the game. Fortunately, developer Cellar Door Games has provided a hidden way to get a 15% increase in the damage you deal to the boss. Let’s go over how to get that important boost.

This boost comes in the form of an Insight you can pick up. Insights are essentially quests that you find during your run through the castle. The Insight you’re looking for is called “Hidden Secrets, Hidden Chambers,” and it’s uncovered by reading Lamech’s fourth memory. These memories are found throughout the game and look like little blue circles of light. However, we’ve found that you might not actually need the Insight to pick up the boost.

What you need to do is find the Tower of Light area in the Citadel Agartha biome. You can see what it looks like in the screenshot above. About halfway up the ladder of lanterns, you need to shoot a spell at the left wall. There’s nothing telling you exactly where to hit, so you might need to play around with it a few times. Once the wall opens, jump in, jump up a level, and enter the door. Within this new area, you’ll find the damage boost, making Lamech much easier to kill.