The son of Sharadvan, Kripa, will surely be on the side in which these two will be. He will never abandon Drona and his nephew (sister's son, Ashvathama).
कृपः शारद्वतश्चैव यत एतौ ततो भवेत्। द्रोणं च भागिनेयं च न स त्यक्ष्यति कर्हिचित्॥