Partha (Arjuna) cannot live without Shauri (Krishna), and Shauri cannot live without Partha. My opinion is that there is nothing unconquerable by these two, namely Shauri and Partha.
न शौरिणा विना पार्थो न शौरिः पाण्डवं विना। नाजेयोऽस्त्यनयोलोक कृष्णयोरिति मे मतिः॥