Can a Chwinga Grant a Given Person More Than one Charm?

So, within the Chwinga statblock, which can be found in Tomb of Annihilation and Icewind Dale: Rime of the Icemaiden, this ability appears:

Magical Gift (1/Day). The chwinga targets a humanoid it can see within 5 feet of it. The target gains a supernatural charm of the DM’s choice. See the Dungeon Master’s Guide for information on supernatural charms.

So, the question is how this interacts with the rule on simultaneous effects. Does Magical Gift linger along with the charm it bestows, or is it an instantaneous effect with the charm simply being bestowed, and thus able to be used an infinite amount of times on a given target without losing the effect of the blessings? (Yes, I am aware of the once per day limit, I’m asking if it could still be used every day to stack up effects, or possibly multiple Chwingas using it all at the same time for the same result)