There are many scary planetary affliction (graha dosh) that happens in the birth chart. Guru Chandal Yoga is one of them. The combination of Jupiter (Guru) and Rahu is notoriously known as Guru Chandal Dosh.
What is Guru Chandal Yoga?
The planet Jupiter is known as Guru in Sanskrit and Chandal (Mlechha) means mean or demon. Hence, it is known as Guru Chandal Dosh.
The planet Jupiter has major role in creating this yoga in your birth chart.
When the planet Rahu and Ketu conjoins together with the planet Jupiter (Guru) in any house is called Guru Chandal yoga.
In some cases, the conjunction of Guru and beneficial Ketu becomes auspicious which is called Ganesh Yoga.