It seems all the Zekvir nerfs have caused him to adapt! He’s now cloning himself and assaulting players!
As we know, Zekvir sometimes pops up in regular Delves and attacks players. After he either drops to low HP or kills the player, he burrows into the ground and leaves. We weren’t aware that a mega-invasion was actually possible, as all reports we’ve seen only featured one Zekvir, which makes sense since, uh, well, there IS only one Zekvir!
Forget Jormungars, It’s Two Zekvirs!
Or insert any Star Wars prequels/Spiderman/LOTR Hobbit breakfast meme here.
Saint_Angelus had a succinct comment on this all-out assault by the Delve uber-boss, with a very to-the-point “So this just happened”.
You cannot escape the Harbinger’s reach indeed. In the end the extremely special event/bug was a happy one, as both Zekvirs were defeated AND dropped loot! One even blessed Saint_Angelus with a 
Delver’s Bounty map, the rarest of rare drops! So if you find yourselves getting tag-teamed by two Zekvirs, know you’re not alone! In the end it’s only fair, it’s you and Brann, so why not Zekvir and Zekvir?