Dead Cells

The Ram Rune will probably be the 4th rune that you unlock, and requires the Vine Rune, and Teleportation Rune. It is earned by going from The Prisoner's Quarters (first area) and exiting through to The Promenade of the Condemned. Near the end, use the teleportation rune to exit through to the Ossuary.

As you work your way through Ossuary, you'll search this large area until you find a large metal door that can be opened with some spikes inside. Once here, you'll have to fight an Elite Slasher. Killing them will drop the Ram Rune, automatically equipped as a permanent unlock. This enemy can do a lot of damage, so it is advised that you dodge and make sure to attack them from behind.
With the Ram Rune equipped, you will be able to smash certain marked floors to access new and secret areas. It will allow us to exit The Toxic Sewers to The Ancient Sewers, which also allows us to fight the boss named Conjuctivius, and unlock the Spider Rune.

This rune is located in the Ossuary, to access this area, you'll need to get the teleport rune. I have described how to do everything in my playlist on YouTube which takes you through each part.

Throughout the area, if you search, you'll find a room with an Iron Door awaiting to trap you and lots of spikes inside.

The slasher has a quick triple melee move with the third being a ranged slash which you can jump over and then a short break before their next combo. This battle will be tough due to the small room which the battle takes place and the abundance of spikes.

Heres a video and below is the full playlist of all runes and areas:

Playlist:
https://www.youtube.com/playlist?list=PL2QolhM4SgygXMJl5CQ6Z...