Kain's Magic Energy was drained by the usage of Spells, Forms and certain Weapons, such as the Soul Reaver. Kain's Magic Meter would automatically refill if unused. It could however, be manually refilled by drinking Blue Blood (that of Ghosts) or by collecting magic spheres. He could also increase his Magic capacity by collecting rune triangles.
Presumably Magic Energy appears in later games, but it is not explicitly identified as such:
- Legacy of Kain: Defiance uses an almost identical 'TK Meter ', consisting of runes (which fill with green energy this time). The 'TK Meter' fills and drains in a similar manner, even having 'TK Runes ' which increase capacity.
- In Blood Omen 2 Kain's combat-based 'Dark Gift' (Fury, Berserk and Immolate ) were filled by blocking attacks and filling Kain's 'Rage Meter', though his other Dark Gifts had no such magical limitations. The Rage Meter likely influenced the design of Defiance's Reaver Gauge (filled by combat and 'Feeding the Reaver') filling this meter also enabled the use of Reaver Spell and Charged Attack, which were arguably magical in nature.
- Legacy of Kain: Soul Reaver featured Eldritch Energy, which enabled Raziel to use Glyphs, These were also arguably magical in nature, although the meter was based on 'points'.
The symbols used for Kain's Magic Meter appear visually to be similar to Blood Script, but meanings are as yet unknown. The same symbols occur on Blood Omen: Legacy of Kain's inventory screen (symbolic of the Pillars that Kain has restored) and in Soul Reaver 2 along the outside of Time Streaming Chamber. Similar symbols are also shown around Blood Omen's Save altars and some spellcasting enemies from Defiance, notably the vampire hunter sorceresses, were able to summon a defensive 'Glyph Shield' with which to protect themselves (albeit with only four runes).