void OnUpgrading()
{
if (CheckGradeListOk(out List <SpiritData> grades))
{
var upgradedSpiritPrefab = Instantiate(
grades[ChoosedSpirit.Data.GradeCount + 1].Prefab,
ChoosedSpirit.Prefab.transform.position,
Quaternion.identity,
ReferenceHolder.Instance.SpiritParent);
var upgradedSpirit = new SpiritSystem(upgradedSpiritPrefab, true);
upgradedSpirit.Upgrade(ChoosedSpirit, grades[ChoosedSpirit.Data.GradeCount + 1]);
upgradedSpirit.SetSystem(Owner);
SpiritUpgraded?.Invoke(upgradedSpirit);
SpiritSold?.Invoke(ChoosedSpirit);
ChoosedSpirit = upgradedSpirit;
}
Owner.SpiritUISystem.ActivateUpgradeButton(ChoosedSpirit.Data.GradeCount < grades.Count - 1);
}
void OnSelling() => SpiritSold?.Invoke(ChoosedSpirit);