I had the exact same months ago. As soon as I got revived I only killed a handful of Harpies which could reach me on top of the pillar. The other two died pretty fast together, so I ran to them, waved and danced on their corpses half-reviving them and went back to the pillar. On the pillar I started shooting the Nexus till he was 1 shot, so I just sat down. After 5 or so minutes they both left, I finished the fight and I got a Legendary.