Damn... looks like making nano armor now needs this nanoscale fabricator, which didn't seem like a big deal until i noticed it requires Krypton and Xenon, and the only way to get those is from The End. In all my years playing minecraft I've never actually gone there. I believe once you do, the only way back home is by killing the dragon right? Which is exactly the kind of thing you need nano armor for. Catch-22 anyone?
A bow with plenty of arrows and a iron armor is all you need to kill the dragon. You could also make a IC2 jetpack if you can't hit the crystals. Just be careful, when you hit them, they explode hard and can easily kill you. You can also install the GT6 weapon mod and kill the dragon with guns, which makes everything alot easier. Nano armor is already OP, it makes sense to put it middle-end game.