Shovel Knight: Specter of Torment

This is a in the Treasure Trove Expansion.

Story related, can't be missed.

The most important tip I can give to help you complete the game is to buy the Will Skull curio as soon as possible. It costs 3 Red Skulls to buy and even if you didn't manage to get any at all from the Plains, there are 3 Red Skulls hidden in the Tower. It costs just under 1 bar of Darkness to use and by default it restores 2 full pegs of Will and 3 full pegs after it is upgraded. It is the most essential curio out of all of them for its ability to significantly prolong your life.

This trophy/Feat, will unlock at the start of the end credits, after defeating the final boss.