By this point, Reen's Ranking Status had regressed.
Eliza had forced her to become a D-Rank demon beast. Reen's bloodline powers were still forcefully active while Eliza was operating on the Array Formation. As such, her lost limbs and flesh kept growing back only for Eliza to rob them again from her.
The regression was escalating at a rapid rate due to this continuous cycle.
'I won't let your trust in me go to waste, Reen. You know what you need to do to make us win big, right?' Eren asked Reen while looking at Reen's feeble state.
'I… I know,' Reen responded. 'Should I…' she asked with some difficulty.
'Yes,' Eren responded while clenching his fists hard, his bones making a crackling sound.
'Al… alright, Erni,' Reen looked at Eren with her clear eyes before leaving a parting message. 'You… you need to know that, no matter what happens, I… aaaaah… I won't blame you. Goodbye, for the time being.