Context: Ruki thinks Alba didn't do anything the last battle, then Alba tells her she wasn't paying attention, reminding her of his heroic feats. Convinced, she says:
soudana, Aruba-kunmo ganbatta ne そうだな、アルバくんも頑張ったね [That's right], Alba-kun worked hard, too, huh.
arigatou Ruki.. ttenani kore!? ude dou natte-n-no!? ありがとうルキ・・って何これ!?腕どうなってんの!? Thank you, Ruki.. wait, what is this!? [What is going on with] [your] arm!?
dou natte-n-no - contraction of dou natte-iru no どうなっているの, literally "what has [it] become."