When it turns into a creature, it is no longer an enchantment.

It changes into a creature even if the spell is countered.

It triggers when the spell is cast, which means it becomes a creature before that spell resolves.

A noncreature permanent that turns into a creature can attack, and its abilities can be activated, only if its controller has continuously controlled that permanent since the beginning of his or her most recent turn. It doesn't matter how long the permanent has been a creature.

Cycling is an activated ability. Effects that interact with activated abilities (such as Stifle or Rings of Brighthearth) will interact with cycling. Effects that interact with spells (such as Remove Soul or Faerie Tauntings) will not.