The generic walkthrough is explained well on the wiki. Make sure to bring Ebon Vanguard Sniper Support as it eases up a lot of the encounters due to one-shotting foes.
Level 1
Run through to Budger Blackpowder and then drop a keg at the Cracked Wall which leads to the gate to level 2 (clear the group of Skelk using leash range).
Level 2
Again proceed through the level, skip most foes, drop a keg at the Cracked Wall and clear the group of Skelk infront of the portal to proceed to level 3.
Level 3
Run past the foes you encounter and place kegs at Cracked Walls until you enter the boss room where you'll encounter Cyndr the Mountain Heart.
The Boss is currently protected by the "Mountain Heart Carapace" which can be removed by drop 3 kegs close to it. The two elementalist spells can be dodged / placed in a irrelevant location when being cast on you, make sure to bait out and dodge the longbow projectile of Pyroclastic Shot before running close to the boss.
After successfully exploding 3 kegs the boss will become vulnerable, depending on your build you might take 2-3 damage rotations to clear the Cyndr.
Completed run as an W/Rt with PvE-Only skills (SoS build with IMS).
Video links
Shiburito R/Rt
Serial E/Rt
Shade A/Me
nightquist pure A
nightquist pure D