I recently had two really good (and long) dragon fights one after the other in quick succession. The first one was an elder dragon, the second, to my surprise was a revered. This character was level 38, so elder was expected (level 40 dragon) but not revered (level 65?). The elder was dealt with quite nicely, his breath attacks were not that deadly, but I had to avoid the bite attacks. It was around the western watchtower, so I had a tiny bit of help from the Whiterun guards, and a giant joined in, but turned hostile and I had to kill it.

The revered was a fight for survival. This was around one of the giant camps, because two mammoths and a giant were helping me. I had help from my summons, and even summoned Dunervihiir (twice) to aid as well. So there were like 9 of us versus 1 dragon. However, one mammoth got roasted and the other got picked up and tossed. The giant was also killed very quickly. I eventually grounded the revered, which made him more dangerous and lured him to Fort Greymoor, where he proceeded to slaughter the imperial guards even with his 'low' health. My fire spells did very little damage. All in all the loot was pretty good, i got 600 gold and a daedric sword. Question: Can you summon two dragons? or will one fly off.