After buying an item in the fountain and undoing the item purchase, you automatically take some damage. If your health was full before going to base, your mana decreases. This is a known issue in the game for quite long time. Could you fix this? [zombie-brand-mindblown]
The champions are actually so attached to the items you buy for them with care, so it physically hurts to have them taken away.
It's not damage, it's a health reset.
It's to avoid abuse cases back before homeguards became standard like, for example, buying an item with a lot of health, then immediately returning it. You retain the health of the item and instantaneously heal at fountain. There's also a shitton of other cases concerning certain item passives/actives.
