In the early stages of the Clone Wars, Ahsoka used a single green lightsaber in her duties serving under Anakin Skywalker and on the front lines of the War. For her, this was enough to get by and keep herself safe on the battlefield… This changed however later in the war when the tide began shifting and Ahsoka was getting into more and more dangerous situations. So how did Ahsoka get her second yellow-green lightsaber?
As soon as Ahsoka was thrown out on the battlefield of the largest galactic conflict in a very long time, she was forced to become proficient in form 4 lightsaber combat known as Ataru with her single blade. This form was an extremely aggressive style for a Jedi, and was filled with numerous elaborate and acrobatic moves. Learning from her master Anakin, Ahsoka quickly became a very proficient fighter in form 4 and proved effective against the droid armies of the Separatists…
Things did begin to change for Ahsoka however after she helped rescue Baron Papanoida daughters, the chairman of Pantora during the Clone Wars. After these startling events, she realized that she needed to improve her defensive ability and especially her proficiency in blocking blaster bolts from droid enemies… As a result, her master Anakin recommended that she take up the more defensive and thoughtful technique called Jar’Kai, which involved using two blades. He knew that this would serve to both improve her defensive skills in blocking blaster bolts but also to take her combat to the next level.
Ahsoka was initially hesitant to incorporate a new blade into her routine, but soon agreed, knowing that it was for her own good. Some time after, Anakin gifted her a lightsaber shoto-hilt, which is basically a shorter and more compact lightsaber hilt similar to the ones shorter Jedi like Master Yoda use. They were also very common among dual wielding Jedi who embraced Jar’kai.