Which asuras were born as hundred kauravas, shakuni, shishupala, jarasandha, shalya and others?
Duryodhana was demon Kali or Kaliyuga and his brothers were demonic sons of Sage Pulastya.
The evil-minded and wicked king Duryodhana, the destroyer of the fair fame of the Kurus, was born of a portion of Kali on earth. He it was who caused all creatures to be slain and the earth to be wasted; and he it was who fanned the flame of hostility that ultimately consumed all. They who had been the sons of Pulastya (the Rakshasas) were born on earth among men of Duryodhana's brothers,...
Adi Parva LXVII
Similarly,Shakuni was Dwapara Yuga.
And the mighty chariot-fighter and king who on earth was known by the name of Sakuni, that crusher of foes, thou shouldst know, O king, was Dwapara himself (the third yuga).
Adi Parva LXVII
Jarasandha, Shalya, kamsa etc were also incarnation of;
"Vaisampayana said, 'O king of men, I shall first tell thee all about those celestials and Danavas that were born among men--The first of Danavas, who was known by the name of Viprachitti, became that bull among men, noted as Jarasandha. And, O king, that son of Diti, who was known as Hiranyakasipu, was known in this world among men as the powerful Sisupala. He who had been known as Samhlada, the younger brother of Prahlada, became among men the famous Salya, that bull amongst Valhikas.
"There was also born on earth a mighty Asura known amongst the Danavas by the name of Kalanemi, endued with great strength, of grand achievements, and blessed with a large share of prosperity. He became the mighty son of Ugrasena and was known on earth by the name of Kansa.
And Karna was incarnation of Narakasura.
The soul of the slain Naraka hath assumed the form of Karna.
Adi Parva CCL