Short answers, pulled from the story.
Maues, also known as Moga, was the first Indo-Scythian king to establish a lasting foothold in the Indian subcontinent. He seized power in Gandhara and the Indus Valley during the first century BCE.
The Indo-Scythian kingdom in the northwestern subcontinent ended when the last Western Satrap, Rudrasimha III, was defeated by the Gupta emperor Chandragupta II in 395 CE. This marked the conclusion of their rule after persisting from the middle of the second century BCE to the fourth century CE.
The migration of the Saka people was triggered by the rise of the Xiongnu confederation which defeated the Yuezhi tribe in the second century BCE. This conflict forced the Yuezhi to flee westward and created a domino effect that pushed the Saka people south from the steppes of Siberia and Xinjiang.
The Indo-Scythians supported Buddhism and played an active role in the dissemination of Buddhism beyond India. They adopted Indo-Greek practices of depicting gods forming the vitarka mudra and dedicated Buddhist reliquaries, such as the Bimaran casket and the Mathura lion capital.
The displaced Saka settled in regions corresponding to Drangiana, later called Sakastan or Sistan, which is a region of south-western Afghanistan, south-eastern Iran, and western Pakistan. They also established kingdoms in Gandhara and the Indus Valley.