The Staff of the First Spinjitzu Master

The First Spinjitzu Master owned two Staffs: one kept inside his tomb as one of the challenges for the Ninja in "Grave Danger". The other had symbols engraved in it, giving clues about the location of his resting place. This was only revealed in season 5.

Pre Pilot
At some point before his death, the First Spinjitzu Master engraved some symbols onto his staff and passed it on to his youngest son Wu. He hid the other one in his tomb.

Way of the Ninja
Sensei Wu uses the staff to attack Samukai and save Kai. He also uses it to activate the training course in the monastary.

The Greatest Fear of All
Wu uses the staff to hit buttons, flip switches and keep open doors to escape with Pythor and Lloyd from Kryptarium Prison.

Winds of Change
After possessing Lloyd, Morro comes to Steep Wisdom tea shop looking for Sensei Wu and the Staff. After a long battle, Wu drops the staff over some chalk, revealing the engraved symbols. Both Wu and Morro are surprised to see the message. Both make for it but Wu manages to get at it first. And tries to escape with it in the Destiny's Bounty.

Ghost Story
Morro chases the Destiny's Bounty on the Morro Dragon to try and gain the staff. He lands on the ship and attacks the Ninja. While Jay, Cole and Nya (as Samurai X) try to fend him off, Wu, Kai and Zane protect the staff. However, despite their efforts, Morro gains the staff and flies it away. Luckily, Wu manages to make an imprint of the message, which is later deciphered by Misako, who said the first symbol was the symbol for Airjitzu.

Later that day, Morro walks into a bar where he lays out the staff on some chalk, revealing the message for everyone to see. He then summons Wrayth.

The Temple on Haunted Hill
Morro reviews the second symbol on the staff, and summons Ghoul Tar and Bansha to help him decipher it.

Peak-a-Boo
Now that they have learnt Airjitzu, The Ninja draw their attention to the second clue, the sword in the clouds, which is revealed to be the Sword of Sanctuary.

A Crooked Path
The Ninja see that the last symbol refers to The First Spinjitzu Master's Tomb.

Grave Danger
The Ninja, Morro and his Ghost Warriors go to the Tomb of the First Spinjitzu Master. After the Ninja complete the first challenge, the second challenge is to obtain the FSM's other staff of creation. They try extremely hard to get it but no matter how hard they try it is impossible to get it. This is when Cole realises they have to think about the clue, "a Spinjitzu Master cannot". In the end they give up and jump down a hole.

Trivia

 * In "Battle Between Brothers" Garmadon breaks Wu's staff by shooting fire at it with the Sword of Fire. This was probably a different staff as otherwise it would still be broken in the future.