As the sun began to dip below the horizon, the battle continued unabated. Thankfully there were no serious injuries due to the low strength level of the creatures. However, Kain and his contracts were running out of spiritual power. Kain could tell that his same-year peers were also in a similar predicament, they've switched to combat styles that conserve spiritual power, and more often elect to use physical attacks that don't even require spiritual power.
The only exception was Serena, who was either foolishly choosing not to conserve her spiritual power, or perhaps she had a quick way to replenish it, such as another higher-level elixir that can be used even after she's already taken the Spiritual Elixir.
'Although…now that I think about it, I don't actually recall her ever taking the elixir…'