Willow does not have long to improve the Wards, that “clamp down” upon her Witchcraft, as her magic is soon required to assist Buffy: raising a “force field” (to help keep an “Uber Vampire” at bay), performing locator spells (to find other potential slayers, before The First can eliminate them), reopening a space/time portal (after Buffy jumped through one) and using a crystal/charm (to help a reformed Andrew remember more about The First).
Willow’s Redemption Spell – In balance, with the Goddess
The final test of Willow’s reformed character occurs when Buffy asks Willow to change the “Slayer” spell: so that all potential slayers shall have the same strength as Buffy (and Faith). Willow is initially scared by the request, as she believes the spell could take her beyond Evil Willow: into a total loss of self control. Fortunately, this turns out not to be the case: and after researching the spell, she is able to cast it with the help of Kennedy (a potential slayer), resulting in Willow glowing in white (and thus being equated with a Goddess). After the “Slayer” spell is successfully cast, Willow collapses from exhaustion; but is able to savour the fact that she has helped to defeat The First, and in doing so, has fully redeemed herself.
As their friendship grows, Tara starts to support Willow in various magical spells. Tara helps Willow float a rose, the intention being to use their magic’s to pluck it’s petals off (one at a time). Willow tells Tara this is a test of synchronisation (as their minds have to be perfectly attuned to work as one). The spells not entirely successful however, as they loose control of the rose and it flies around the room (bouncing off the walls), and they end up burning all the petals off in one go (owing to interference from some darker magic that’s at work that evening).
Later, when Willow first introduces Tara to Buffy, a test of their new friendship occurs, as Tara tells Willow that Buffy is not herself. Being able to read Buffy’s aura, Tara tells Willow that there’s something wrong with Buffy’s: its fragmented (like something was forced in), whereas it should be aligned (having energies that flow in unity). Tara tracks down a spell that Willow can use to travel to the “Nether Realm”, where Willow can find out what’s happened to Buffy. Tara says that the journey shall be like astral projection (i.e. very intense), and that she shall have to be Willows anchor (to help keep her on this/earth’s plane). The spell involves Willow and Tara forming a protection circle, by moving their arms around them (in a semi-circle), which eventually leads to the circle being traced by fire. Willow is then able to enter a state of trance, where she travels to the “Nether Realm” and sees that Buffy’s soul has been swapped with Faith’s (that of a “bad” vampire slayers). Willow and Tara are then able to conjure a “magical device” that can swap Buffy’s and Faith’s souls back.