Alms are a plot point in Visions of Mana. The term refers to spiritually powerful people with a strong connection to the Elemental Spirit overseeing their region. They are selected by the Faerie to make a pilgrimage towards the Mana Sanctuary to sacrifice themselves to the Tree of Mana and sustain the flow of Mana Power with their Corestone.
Alm sacrifices are indispensable to sustain the flow of Mana Power. Should an Alm refuse it's duty, the depletion of Mana Power would lead to magical and natural disasters and eventually wipe their homeland from the map. As such, alms are revered for enabling a future for the generations to come.
While the tradition of the alms' pilgrimage has been deeply ingrained in every culture over the millennia, to the point of being anointed as one is considered the ultimate honour, others such as Eoren or Master Passar grow to resent it. The latter selfishly scorning their sacrifice, the latter regarding it as a dire injustice to be terminated at any cost. Khoda, who sacrifices them to turn them to Corestones is well aware that this amount to a human sacrifice and deeply grieves being reduced to this extremity to save the dying world.
It turns out that millennia before the start of the story, civilizations waged the gruesome Ahrvet's War, misusing the Mana Power to the point of angering the Benevodons, who went into a rampage. Alas, even with the Beasts sealed and peace restored, Mana has dropped so low that the Five Realms merged into one, turning the world of Fa'Diel into the world of Qi'Diel. Alms were needed as sacrifices every four years to sustain the flow of Mana Power, becoming ones with the Tree while their souls went to the Ethereal Sea to await reincarnation, in a way similar to that of women from the Mana Clan becoming one with the Tree to succeed the Mana Goddess.
After defeating Daelophos with his friends, Val was bestowed the Sword of Mana by the Goddess as the new Mana Knight. He then used its reality-warping power to restore the world of Fa'Diel, ending the need for Alms forever.