Mark Waid said very little about Damian in recent interviews, but he did say this:
"Mark, what else can you tease about the final issue of Batman vs. Robin, with Lazarus Planet looming on the horizon?"
"I can tease the final showdown between Robin and Nezha. I can tease that you're going to see a chase scene in Batman vs. Robin #5, the likes
of which you've never seen before. You're going to see Damian make a jaw-droppin sacrifice in that issue"
What do you guys think this sacrifice will be?
Damian becoming a living prison for Nezha à la Raven? Sealing Nezha and himself in Nezha's tomb from the inside since that's apparently the only way to do it? Something completely different?