The Trickster and the Fool:

In Trickster is one of the Jungian Archetypes. By wikipedia, the Trickster is:
"The trickster [...] breaks the rules of the gods or nature, sometimes maliciously (for example, Loki) but usually with ultimately positive effects (though the trickster's initial intentions may have been either positive or negative). Often, the bending/breaking of rules takes the form of tricks (e.g. Eris) or thievery. Tricksters can be cunning or foolish or both; they are often funny even when considered sacred or performing important cultural tasks. An example of this is the sacred Iktomi, whose role is to play tricks and games and by doing so raises awareness and acts as an equalizer.
[...]
Frequently the Trickster figure exhibits gender and form variability, changing gender roles and even occasionally engaging in same-sex practices. Such figures appear in Native American and First Nations mythologies, where they are said to have a two-spirit nature. Loki, the Norse trickster, also exhibits gender variability, in one case even becoming pregnant. He shares the ability to change genders with Odin, the chief Norse deity who also possesses many characteristics of the Trickster."

The Fool seems to fall squarely into the category. Clever, cunning, whimsical, and ultimately fluid.

Tricksters seem to help humanity, but their helping is more often than not a mixed blessing. Coyote in the native myths give fire to humans, but he also brings death. Prometheus (another Trickster) also steals the fire, but his action bring to humanity all the Evils (death, illiness, famine... but also hope) in the form of Pandora.

Often, Tricksters marks ending and beginning, typically the one between a mythical "Golden Age" and the modern one. The Snake of the Genesis is a Trickster, and Mankind will forevermore be banished by the garden of Eden. Coyote and Prometheus brings fire and hope, but humans will forevermore die and the Golden Age is ended. Strife will begin.

More than help, what the Trickster brings is *awareness*. The Tricksters make human aware of what means to be humans, and not beasts. Fire (or the more metaphorical but equivalent "knowledge of Good and Evil") and Death and Hope are the hallmarks of humanity.
The Trickster, and perhaps the Fool, mixed gift is that He makes us aware of it. In good and ill.

(Also, his relationship with his Catalyst (Fitz) falls into another of the patterns often see in relationship to the Trickster:

"In some cultures, there are dualistic myths, featuring two demiurges creating the world, or two culture heroes arranging the world — in a complementary manner. Dualistic cosmologies are present in all inhabited continents and show great diversity: they may feature culture heroes, but also demiurges (exemplifying a dualistic creation myth in the latter case), or other beings; the two heroes may compete or collaborate; they may be conceived as neutral or contrasted as good versus evil; be of the same importance or distinguished as powerful versus weak; be brothers (even twins) or be not relatives at all."

Loki and Odin are a good example of this.)