Based on the details provided, X is Arjuna and Y is Bhagadatta. Arjuna had to go to Manipur to retrieve the sacrificial horse when it was stopped by the king of Manipur, Bhagadatta. In the ensuing battle, Arjuna was killed by Bhagadatta. Later, Arjuna's wife Subhadra used a gem that could revive the dead to bring Arjuna back to life.

2. B1.
X opposed the Indian National Congress's decision to grant Kashmir a
special status with its own flag and Prime Minister. In opposition to
this decision, he once said "Ek desh mein do Vidhan, do Pradhan aur
Do Nishan nahi challenge".
X went to visit Kashmir in 1953 illegally, and observed a hunger strike
to protest the law that prohibited Indian citizens from settling in a
state within their own country and mandated that they carry ID cards.
X wanted to go to Jammu and Kashmir but, because of the prevailing
permit system, he was not given permission. He was arrested on 11
May while crossing the border into Kashmir. Although the ID card
rule was revoked owing to his efforts, he died as a detenue on 23 June
1953 under mysterious circumstances.
Atal Bihari Vajpayee claimed in 2004 that the arrest of X in Jammu
and Kashmir was a "Nehru conspiracy”.
Identify X.

5. F5
 Carsten Fischer
 Stephan Veen
 Rechelle Hawkes
 Dhyan Chand
 Leslie Walter Claudius
 Roop Singh

8. G5
What system was introduced during 15th century into the
rest of Europe and the world by Venetian glass blowers to
protect their skills against those of local workers?

10. Patent System

11. H5
Distinctive Assets has been providing “Swap bags” to celebrities that
have achieved certain feet.
These swap bags are worth $45000. There are some pretty odd gifts in
these swap bags. In addition to Windex and Diet Pepsi, the gift bags
include unusual items such as a $600 acupuncture session, Gleener:
The Ultimate Fuzz Remover, a water purification system, Condoms,
the artwork “Abraham” by Dan Duff, the bottle of Bonita Platinum
Tequila and the Njoy King electronic cigarette, $12,000 tropical
Australian holiday trip.
What feet is achieved by those celebrities to get such weird and
marvellous stuff?

13. And “SWAP BAGS”

14. Yuddhisthira performed ashwamedha yagna . The sacrificial horse goes to
manipur and stopped by king of manipur. So one of the pandavas (X)have to go
and defeat the king of manipur(Y).
Y was son of X and in that fight that X was killed by Y . Later X’s wife uses gem
that can revive dead people and bring X to life.