Question

The yadava ruler who fought with kakatiya Rudramadevi?

Answer 1

Mahadeva is the answer.

Answer 2

Mahadeva.
Mahadeva Raja, the Seuna Yadava ruler of Devagiri from the West came to Warangal - Orugallu - fort and attacked the Kakatiya kingdom.  The other kings were jealous of a woman becoming the ruler of kakatiya dynasty.

Rani Rudramadevi defeated Mahadeva Raja and drove him back over a long distance.  He made peace with her finally.