Short answers, pulled from the story.
Maues became the first Indo-Scythian king around 85 BCE and established power in Gandhara and Taxila. Azes I took control of northwestern India in 55 BCE by defeating Hippostratos, an Indo-Greek king.
The Saka people moved from their homelands in the Tarim Basin toward Bactria and present-day Afghanistan during the second century BCE after being displaced by the Yuezhi tribe. This migration continued until they reached Sakastan, a region corresponding to modern-day Drangiana which later became known as Sistan.
Indo-Scythian rule ended when the last Western Satrap Rudrasimha III was defeated by Gupta emperor Chandragupta II on the 395th year CE. Earlier conflicts included campaigns where Rudradaman I conquered the Yaudheyas and defeated parts of the Satavahana Empire.
Excavations at Taxila revealed stone palettes found only in layers corresponding to Indo-Greek, Indo-Scythian, and Indo-Parthian rule. These artifacts were discovered exclusively in archaeological layers tied to these periods and never in preceding Mauryan or succeeding Kushan layers.
Silver content decreased over time while bronze content increased suggesting a lack of wealth during periods of decline. Coins minted under Rajuvula deteriorated near the disintegration of Indo-Scythian rule around 70 CE.