Pain Box

In Castlevania: Lords of Shadow, the magical crystals that increased the strength of the mighty hero Gabriel Belmont were found and collected by searching the corpses of fallen members of the Brotherhood of Light, the monster-hunting organization Gabriel belonged to.

However, in Castlevania: Lords of Shadow 2, Gabriel has since been transformed into the Vampire Lord Dracula, and uses unholy artifacts and dark magic to increase his personal power, not the holy relics and sacred spells that he used as a mortal, so the equipment of the Brotherhood has become useless to him.

Therefore, while he can still search the corpses of Brotherhood soldiers to read their journal scrolls and gain new lore, Dracula has devised a new method of increasing his power; before the start of Lords of Shadow 2, in which he was robbed of most of his strength during a five-hundred year sleep, he put magical crystals that can increase his power into devices called Pain Boxes and placed them throughout his realm. Now, having awakened from his slumber at a fraction of his former power, Dracula must track down the Pain Boxes, which are scattered throughout both the modern-day Castlevania City and the surreal, otherworldly Dracula's Castle, and gather their precious cargo in order to regain his strength.

The Pain Boxes themselves are magical artifacts in the form of indestructible metal crates that hover off the ground and are surrounded by spinning metal rings. As Dracula approaches, the Box rotates to face him and the rings stop spinning, locking in place without blocking the noticeable hole in the front. When he sticks his arm inside, spiked rods on the inside stab through his flesh, causing him to bleed profusely onto the ground, hence the name of the container. With this sacrifice made, the Pain Box dissolves into nothingness, leaving Dracula with his prize in hand and his bleeding wounds (which do not actually lower the player's health mater) already healed thanks to his vampire physiology. It is unknown if anyone can access these Pain Boxes, or if they are magically attuned to Dracula's blood, the way the magical Map Rooms will poison anyone else who attempts to use them.

Pain Boxes can contain one of three kinds of magical crystals; Void Crystals, which when collected in groups of five will increase the amount of void magic Dracula can carry and use to power his icy Void Sword, Chaos Crystals, which similarly increase his ability to use the fiery Chaos Claws, and Life Crystals, which are the most coveted of all, as they increase the size of Dracula's health meter, making him an even more formidable warrior of the night. While Pain Boxes are surrounded by a pillar of light to make spotting them easier, Dracula can also take the trouble of locating them himself out of the equation entirely by using a Dodo Egg relic to hatch a dodo bird that immediately seeks out a nearby Pain Box, temporarily marking its location on the map.

In the "Revelations" DLC chapter for Lords of Shadow 2, players instead control Gabriel's son Trevor Belmont, now the vampire known as Alucard. Instead of tracking down Pain Boxes, Alucard can find upgrades hidden inside Secret Boxes, which are functionally identical but radically different in design. Alucard merely has to open them up, for one, rather than sacrificing some of his blood to unlock the container, and because Revelations is much shorter than the main campaign, instead of having to collect five crystals to earn an upgrade, every Secret Box contains a full upgrade to Alucard's health, or the Glaciem or Igneas magic in his sword, Crissaegrim (which are functionally identical to Dracula's Void and Chaos magic, respectively).