Codex

The Codex is a magical object divided into the four pieces, that when united with Light and Darkness, open the realm of Relix.

Overview
The Codex is the key to Relix and it can only be used to open the portal to the Relix in the presence of both Light and Darkness. The Codex is divided into four pieces looking like four crystals, each protected by a Guardian Pixie, found at Alfea, Red Fountain, Cloud Tower and Pixie Village. Each Guardian Pixies also possesses a copy of the Codex which looks like a gem in a pendant.

Opening the Portal of Relix
To open the portal of Relix, the four pieces of the Codex must be brought together and a spell needs to be used. The balance between Light and Darkness must be respected to open the portal and to gain the Ultimate Power of the Realm of Relix, which is why Darkar had Bloom kidnapped and turned her into Dark Bloom.

Codex Pieces
One piece of the Codex is hidden at Alfea in the Secret Archives, protected by the pixie Concorda. The second piece at Cloud Tower is hidden in the heart of the tower, protected by Discorda. The third piece at Red Fountain is hidden in a weaponry base, protected by Athena. The last piece of the Codex is in Pixie Village, as part of the Pixie Queen's scepter, guarded by the Pixie Queen herself, Ninfea.

Codex
It is an elliptical ivory grey object that has ancient scripts on the surrounding it is covered by a cyan/light blue glow.

Copied Codex
The copied Codex all somewhat look similar to a brooch.
 * Alfea: It is gold with a red gem in the middle, it has a somewhat bug-like shape.
 * Pixie Village: It is in the shape of a gold flower with a pale blue gem in the middle.
 * Red Fountain: It is silver with a longer shape, with a longer thin purple gem in the middle.
 * Cloud Tower: It is silver with a tear drop-shaped orange gem in the middle, while the part that is around the gem is in a shape resembling a pumpkin's.

Season 2
Lord Darkar originally thought that the Codex was in the Pixie Village, but after gathering information through Kerborg, he found that it consisted of four pieces: one in each of the three schools of Magix and a fourth piece in the Pixie Village. Each of these pieces were protected by a Guardian Pixies.

Throughout the season, Lord Darkar obtained the pieces of the Codex guarded by Red Fountain, Cloud Tower and Pixie Village with the help of the Trix, and he got the Alfea's piece of the Codex through Bloom, whom the clone of Avalon that Darkar had sent to Alfea, had temporarily infected her with a dark virus, turning her into Dark Bloom for the first time.

Faragonda had a copy of each Codex piece made after Lord Darkar's return in Season 2 as a precaution in case he managed to get hold of the pieces found in the three schools and at the Pixie Village, which indeed happened. When Lord Darkar kidnapped Bloom and turned her into Dark Bloom, he then opened the portal of Relix with her help and after entering he sealed the Portal.

Later, the Winx arrived at Darkar's Fortress trying to rescue Bloom but were unable to enter Relix. The Guardian Pixies then used their copied Codex to open another portal, but found they had to solve the Codex Cipher in order to gain access to Relix. The puzzle was in the form of many color strips which had to be arranged in a specific pattern, which Stella did by following her fashion instinct, which opened the portal.

The Shadow Phoenix
In this Special, the Codex is one piece, which is kept in Pixie Village. Ninfea gave it to Icy after she threatened to freeze the entire village in ice. The four guardians of the Codex can open the portal to Relix without the Codex.

Trivia

 * Codex is the Latin word for "book" and "tree trunk" and is used to refer to:
 * an early manuscript book
 * a book bound in the modern manner, by joining pages, as opposed to a rolled scroll
 * an official list of medicines and medicinal ingredients