Just copied from Discussion 19 thread, for those who don't like spoilers:
Eternal fairies (those things that kinda resemble nymphs from the first season) are asked to help winx. For each mission they will get gift of destiny (that, I suppose will last only for that mission, but not sure) and for this one they gained sofix.
If I understood well, gifts of destiny amplify believix powers, and this one (sofix) does that for those "special" believix powers.
"New" sofix "attacks":
Bloom:
Fiama interiore (internal flame) - This is power that increases internal strength of creatures, they will to revive...
Stella:
Luccio del Lucce (pike of light) - This is light of hope that will never be put out
Layla:
battito vitale (vital heartbeat) - This is internal heartbeat, the natural rhythm that souldn't be broken.
Musa:
pura harmonia (pure harmony) - Power of harmony and serenity.
Tecna:
ordine superiore (superior order) - Gift of order, reason and structure of things.