Looking at her lovely face, Kentaro couldn't help but shed a tear. He knew her for only one day but she was very kind to him, it pained him to see her like this.
Though I could beat Annie on a 1 on 1, if its Reiner and Annie, it could spell some trouble, and if it is Annie and Bertolt, Ill have to reveal my size titan. If its all three, then there is no doubt Ill have to reveal my size Titan and unlock a portion of my human limiter. Eren is useless in this fight. He is too inexperienced in martial arts, and hasn't even unlocked 50% of his titan limiter, only 42%.' Thought Alex. He looked above the wall before dodging to the side from a kick from Annie. Opening his mouth, Alex talks slowly.
{The way to get chakra in this world is to get into the coordinate. There are a few requirements needed for you to get Chakra. First, you need to possess all 9 titans. Not ones from previous years before these 2000 years. The second condition is to be in your titan form while in all 9 of these forms. The third condition is to get into the coordinate, without any kind of constraints, like the one of the Royal blood. The last condition would be to walk into the coordinate. Once you have done that, the titan powers in you, that aren't the 9 Titan powers, would strengthen, making this world stronger, which would let you cultivate Chakra once again, however, you wouldn't even be able to get all the Chakra you had from the Naruto world here, since Chakra isn't based here. The downside is that with this, everyone in the whole Attack on Titan-verse will be able to cultivate Chakra.
Now to discuss another issue about the 'Sin Seal'. It's a part of the plot. The MC can't spam jutsu one after another and run amock because of the seal. He has to be conservative with his chakra. This forces him to train chakra control and squeeze out every last bit of his chakra.