When she returns from Earth 1, he notices the light in her eyes - those extraordinary comet eyes - had gone out.
She needs a day and a half of stasis under the UV lamps at the DEO after coming through the breach, her sister holding her up right. She stumbles when their eyes meet, sways a little on the spot and collapses. He speeds to her, catching her before she hits the ground, brushes the hair out of her face and stops dead. He cannot believe what he is seeing. She is all Kara - no vestiges of Supergirl, dressed in a pair of inexplicable blue scrubs, stained red with blood. Her blood. He feels rage flood his belly and warm him with purpose. He is vaguely aware of Imra behind him - can feel both the confusion and concern for Kara coming off of her in waves.
Alex refuses to look at him, refuses to tell him what had happened, just barks for Winn to call Kal-El and shuts the glass door in his face with a seething glance. It isn't until many hours later, when he has been shut down by every member of the DEO, under Alex's explicit instructions, that he begs his wife to use her telepathy to find out what happened to his girlfriend.
The irony is not lost on him.
Nor Irma who, bless her, just arches an eyebrow pointedly before closing her eyes. The air around them thickens and shimmers, almost imperceptible to the naked eye. Within moments, her expression darkens, turns stormy. Imra lets out a soft gasp and reaches for him, transporting him through his wife's telepathy, behind his lover's comet eyes, and into her nightmare.
Kara's subconscious is filled with pain, both physical and psychological. They feel her agony, her fear and possibly worst and most Kara of all, the overwhelming feeling of failure she feels for letting down her friends. Images, out of context but striking all of the same, flood his mind. Swaztikas, a mass grave, a firing squad, the high pitched mechanical whir of a saw and Kara but not, in an 'SS' uniform, a scowl across crimson lips as she taunts her victim...
" Why do you care if I take your heart? You're not using it... "
It isn't until Imra releases him from her grasp that he realizes both of their eyes are bright with tears.
He finds his old place of employment by sense memory and drowns himself in zakarian ale. Mon El intends to drink himself stupid, until he forgets the sound of Overgirl's voice and Kara's suffering. After all, he cannot comfort her. Cannot alter the timeline. So, he drinks to forget the electric feeling of her probing hand reaching beneath his shirt and the brightness of her eyes. He drinks to forget the hurt he felt rolling off of her as he kissed Imra, drinks to suppress the urge to take her in his arms and show her how much he regrets it. He drinks to stop himself from trailing his lips down her jaw and showing her how he would've given anything in the last 7 years to see her face just one more time.
He almost succeeds. Until he comes in, dressed as the mild-mannered reporter from Metropolis. Mon El doesn't turn when he enters, not until he feels the tap on his shoulder and turns...
He had forgotten, he admits begrudgingly as he scrambles to his feet, exactly how strong Kryptonians are on this earth. The impact of the punch knocks him off his stool, splintering it in the process. He skids across the floor and lands in a heap beside the jukebox. Kal, for his part, does not acknowledge him as his ally from the Legion, because – of course - he is the Superman of this century, not Mon-El's best friend from the 31st. All he sees is the Daxamite who broke his cousin's heart.
Kal does not speak for a moment, nor does he advance - thank Rao, Mon El thinks. Just stands there, regarding him as if seeing him for the first time. Finally, he lets out a resigned sigh and turns his back, settles himself into the stool next to his wreckage, and signals the bartender for two more - an unspoken invitation.
They are quiet for a long while, watching the bartender. Finally, when their drinks are set in front of them, Kal takes a long drag and regards him again.
" Imra showed me. I was furious when I spoke with Alex. I would've thrown her out of the DEO but she showed me... what Kara went through."
Mon El nods.
" That why you just swept the floor with me? "
" Partly. No Nazi's to punch. Also, Alex asked me too. " Kal grins, despite himself as he take another drink. His expression sobers as he continues, " Overgirl was wrong. Kara is still using her heart. But you already know that... in that moment though, with that saw bearing down on her, you could feel as well as I could, thanks to your wife, that she thought about it... " Kal-El's voice breaks. " She thought it might hurt less. Thought that you took her heart when you left anyway. You know as well as anyone she would've gladly let them crack her sternum to save Alex and Barry and the others, to save me and despite it all, to save you. "
" Don't you think I know that? " Mon-El explodes, all of the grief and all of the sacrifice pouring out of him. " Well, here's what you don't know, Clark. What I saw. What I went through to save her. I held her in my arms, the scorched earth all around us and I told her I loved her as I watched the light fall away... And you? You were too late to help her, too late to save her. And we wept. I know what it's like to walk around without your heart because I have been doing it every day for the last 7 god damn years. "
Silence again, thick and filled with disbelief. Kal hangs his head for a moment, breathing deeply. When he looks up, Superman's eyes are filled with unshed tears. Mon-El is overcome by the thought, sudden and unbidden, that next to Kara's lifeless form, it is the second worst thing he has ever seen.
" In the future, your future... Kara is gone? "
Through the thick fog of his memories and grief, Mon El can only nod. And in the blink of an eye, it all changes. It's almost as though he can feel the timeline shift, feel it alter. He can hear Imra's warning, clear as any telepathy. But in that moment, he fears not the wrath of the Legion, nor the consequences for his marriage. He knows, despite her talk, that if given the opportunity to do it over – if standing in front of her first love – she would do the same thing. So, Mon-El – selfish crown prince of Daxam, makes a choice to save her because he knows now that he cannot lose her again. Knows deep in his gut that he will not survive losing her again.
And with that realization, the two men who love Kara above all else, a Kryptonian and a Daxamite - begin to conspire to save her life - consequences be damned.