Short answers, pulled from the story.
Maues was the first Saka king in the Indian subcontinent, with a reign dated approximately 85-60 BCE. He conquered Gandhara and Taxila around 80 BCE, establishing Saka power in the Indus Valley and surrounding regions.
Indo-Scythian rule in the northwestern subcontinent ended in 395 CE when the last Western Satrap, Rudrasimha III, was defeated by the Gupta emperor Chandragupta II. The Western Satraps had controlled Kathiawar and Gujarat until that point.
The migration began as a domino effect triggered when the Xiongnu, under Modu Shanyu, defeated the Yuezhi around 175 BCE. The displaced Yuezhi in turn pushed the Saka southward, and subsequent Yuezhi defeats after 155 BCE drove the Saka further toward Bactria and eventually into the Indian subcontinent.
The Indo-Scythians were closely associated with Buddhism. Multiple kings made Buddhist dedications, including Patika Kusulaka, who donated a relic of the Buddha Shakyamuni, and Indravarman, who dedicated the Bajaur casket in 5-6 CE. Their coins frequently display Buddhist symbols such as the triratana and the Buddhist lion.
Indo-Scythian coins follow the Indo-Greek tradition of using the Greek alphabet on the obverse and Kharoshthi script on the reverse, but replace a royal portrait with images of a king on horseback, on a camel, or seated cross-legged. Greek gods appear on the reverse alongside Buddhist symbols such as the triratana and the vitarka mudra gesture.
Indo-Scythian soldiers appear in Buddhist friezes, especially the Buner reliefs, wearing loose tunics with trousers, pointed hoods or the Scythian cap, and carrying heavy straight swords. These friezes decorated the pedestals of Buddhist stupas and show Indo-Scythians alongside figures in Greek attire, as well as in scenes of music and dance.