Each stage gives Soul Stones the first time you clear it, and never again. Chests and enemies do not drop them.

That is exactly what the whole Engraving tree costs, so every special node can be learned once all 160 stages are cleared.

40 for the 40 stages of Normal.

120 for the 40 stages of Torment.

200 for the 40 stages of Nightmare.

280 for the 40 stages of Hell.

Each enemy you defeat gives Souls: 50 on Normal, 60 on Torment, 70 on Nightmare, 90 on Hell, before bonuses.

While the game is closed you keep earning. For 8 hours offline, before bonuses: 203,000 to 414,000 on Normal, 425,000 to 540,000 on Torment, 532,000 to 643,000 on Nightmare, 664,000 to 772,000 on Hell, depending on the stage.

The Workshop turns gear you do not need into Souls. Each gear page lists what every rarity gives.

Soul on Kill nodes add up to +190.08%, Offline Soul nodes to +49.99% and one node gives Offline Rewards +20%.

Soul on Kill +5% · Clear stage 1-10 on Normal

Offline Rewards +10% · Own the Convenience Pack DLC

Soul on Kill +5% · Own the Trade Pack DLC

Normal Engraving nodes cost Souls, 1,153,652,360 for the whole tree. Workshop recipes, skills and heroes cost no Souls.