In Valley of the End, chakra is narrative and 5e represents shinobi combat. Here, bending, chi, and spirit power are narrative, and 5e represents the fight.
WHAT THAT MEANS
A @Water Whip may be implemented as a spell, a maneuver, or a weapon-like attack in Friends & Fables. In the fiction, it is a waterbender moving water. Do not describe verbal components, spell slots as 'magic missiles,' or arcane glyphs unless a particular ritual actually uses marks and chants (Fire Sage rites, Pai Sho as recognition, a spirit bargain). The player should still be specific: I spend one Flow to use @Water Octopus Form.
SOURCES AND LIMITS
Fire: breath, drive, a steady chest. Cold, smoke in the lungs, drowning, or a crushed ribcage hinders firebending. Sozin's academies teach sharp, aggressive forms. Older sun and dragon styles are fluid and life-based. Sozin is already changing what 'proper' fire looks like.
Water: a source — river, ice, gourd, sweat, plants, or trained moisture from air. The moon strengthens waterbenders. A solar eclipse or a truly dry room weakens them. Healing is a known art in this age, not a future invention.
Earth: contact with earth, stone, packed soil, or (if trained) sand. Being lifted off the ground is a real problem. Neutral jing: wait, listen, then commit.
Air: breath and space, not a hauled source. Tight sealed rooms, vacuum, or heavy gas still matter. Roku used air to hold back volcanic fumes; that is a form, not a miracle with no limits.
Nonbenders: timing, weapons, chi-blocking if trained, terrain, numbers, and nerve. A Yuyan shot or a Kyoshi fan can end a bender who is careless.
ENVIRONMENT IS A RULE
Sooty air, packed earth, open sky, a full moon, a comet in twelve years, a spirit-sick forest, a canal at night — describe them and let them change the roll. The GM should honor stance and terrain.
SUB-BENDING IS NOT A STARTING SUBCLASS for most people. Healing, plantbending, sandbending, and seismic sense may be learned with the right teacher or spirit-animal tradition. Lightning, lightning redirection, metalbending, bloodbending, combustionbending, true flight, spiritual projection, and the air scooter are rare, forbidden, lost, or not yet invented. See the lore page on forbidden arts. Player discoveries should be marked as discoveries, not retconned as 'everyone knew this in 12 BG.'
THE COMET is not a trainable spell. During Sozin's Comet, firebending is catastrophically amplified. That is an event, and it is the doomsday clock.