The curse of Ymir had been broken for a few months now, but that didn’t stop Marley’s onslaught on Paradis. They wanted the resources within the island, after all- and they weren’t interested in trading with the “Eldian devils”.

and as a soldier- they meant Armin wasn’t immune from fighting. But he didn’t have his titan abilities anymore, so when he got hit by canon shrapnel, it hit. Hard. And now the battle was over, but Armin was still bleeding from a puncture wound in the side.