If Gilgaran would take damage instead prevent that damage and put a -1/-1 counter on Gilgaran.

If Gilgaran would die instead put two -1/-1 counters on it, unless it would die from having its toughness reduced to 0.

If Gilgaran would be exiled instead put three -1/-1 counters on it.

At the beginning of your upkeep you may remove a counter or unnatach an artifact or enchantment from Gilgaran.