Everywhere in this crossover.
- The defeat delivered to humanity by Behemoth with Taylor having no way of knowing if any of her other friends survived.
- When Taylor learns that she has been displaced into the future and that the odds of her returning to Earth are nonexistent, not even including how different and bad things have gotten there.
- The fact that Scion destroyed Taylor's Earth meaning her getting back really is impossible. As well as the reason it happened was because she got displaced from her universe to begin with (not that she knows this).
- The sacrifices made by several notable individuals in Taylor's forces. A dying Larkine using a grenade to kill several Eldar on the Battle Moon. The Wuhan soldier who took the blow that Ka' Bandha tried to use against Taylor. Theodora Gaius's sacrifice to save Rogal Dorn from the Demon using Fulgrim's body and how one of her subordinates fights desperately to reach her body.
- The Black Templars' reaction when they're finally reunited with their gene-father, only for him to leave them less than an hour afterwards. At least one Marine is sobbing under their helmet.
- When the Imperials realize that it is impossible to save the billions of human slaves in Commorragh, because the Imperium lacks the means and the time to ensure they will live. For many, a Mercy Kill is the best thing, and even more choose to fight against the Dark Eldars as their final act of revenge on their torturers.
- For more precise numbers, they estimated 30 slaves of various races for each Dark Eldar. Apply that to a Drukhari population of 187.6 billion, and you get a lowball estimate of 5.6 trillion slaves. That's more than a hundred thousand times the size of the task force that attacked the Dark City. Even if they could pack every ship in the fleet to the gills they still wouldn't have been able to fit a thousandth of the slaves in there.
- Lelith's past is also one if you consider the fact that she was a hero who constantly fought to defend her people only to be disgraced and exiled. The very thing she tried to stop happened anyway and the Eldar hadn't truly learned anything as they kept repeating the mistakes that caused it. It has reached the point where she doesn't even see the Eldar as her people, has abandoned the promises she made to Vaul, and spares Taylor knowing how dangerous she can become if allowed to grow.
- When Cegorach asks her to take Maea Teallysis as a student, Lelith somberly reminds him her last student (strongly implied to be Arhra Turns out it was the former Muse of Khaine Hekatii .) betrayed her during the First Fall and she is worried about a repeat. Lelith is old. She has seen a lot, including the worst of her species, and she is still bitter over it.
- The Emperor finally gains the freedom to see what has become of Terra and can only weep to see how the Imperium has fallen. Ultimately he has to give up his old dream of humanity's future in order to move forward.
- Hundreds of millions of slaves have been freed from the Dark Eldar - but have to be killed since there is no way to evacuate them out of Commorragh.
- The butcher's bill for the Battle of Commorragh: more than twenty-three million soldiers (plus the above-mentioned slaves) died in order to finally put an end to the Dark Eldar and their depravations.
- Just to drive the point home, during the ceremony on Pavia the various units of the Imperial ground forces are assembled and many are represented by only a few young soldiers obviously sent away when the veterans realized they were going to be wiped out.
- It becomes one for 40K as a whole when Lorelei Moltke notes that the 23 million military fatalities, which amount to roughly 46% of all human and transhuman combatants, is not the bloodiest battle she'd ever seen, both proportionately and in absolute numbers. And the wars of the 36th Millennium are likely tame compared to those coming in the 42nd Millennium. At least Commorragh could boast a successful mission that broke the Dark Eldar as a galactic power. The bloodier campaigns likely didn't achieve even a tenth as much in the big picture.
- In a minor way, the Alas, Poor Villain fate of Rogue Trader Vanessa Armengrade, who doesn't try to deny her actions or protest Taylor's judgment but can only offer an excuse of desperation and concern for the lives of her crew when all of them are sentenced to die anyway.
- The Lonely at the Top lamentations of General Paul Oberstein. He only has his dogs to comfort him, and the demands of his office are so constant that he can't even spare a few minutes a day to properly exercise them anymore.
- Sophia briefly glimpses the truth of the Emperor's Ascension on the Golden Throne — constant suffering, without any hope of respite, merely the slightest improvement to his unending torture session. It's enough for her to pity him.
- Also, she first sees him as a monstrous Knight Templar, the kind who can give you nightmares on sight. The Emperor forlornly notes she's the first one to envision him this way since Konrad — the Emperor's very son was terrified by his father and thought he was a monster.
- For all the pleasure of seeing Biel-Tan finally destroyed, the Exarch who oversees the battle lends the situation a feeling of melancholy. He sees entire halls of the Craftworld have been empty for decades or even longer, victims of their endless war on the stars.
- Surprisingly, Malicia of all people gets two.
- One when she rages against the Simurgh/Ziz for continuing to screw over Parahumans, even millenia into the future.
- The second is when she contemplates what she's become, thanks to circumstances beyond her control - chiefly, Amy completely screwing up her body, and being forced to make a pact with Tzeentch to be transformed back - only for Tzeentch to screw her over and make several alterations of its own to her.
- As is canon, the relationship between Vargard Obyron and Overlord Zahndrekh is equally this and Heartwarming. Obyron is ferociously loyal to his suzerain and cares deeply for him after he raised him from peasantry and all the way to the "man" he is now, and he still admires him to this day. But he can clearly see Zahndrekh no longer has his wits and how the Great Sleep has damaged his mind, and it saddens him to no end.
- Commodore Yang Wen-li was aboard the starship Spirit of Eternity when it was lost in the Warp and reemerged almost ten thousands years later. Needless to say, the contrast between the 24th millenia and the 35th is huge, and really not favoring the future — the Commodore almost Laughing Mad when he hears just how low humanity fell.
- Rafaela Harper's death. Too gravely injured in the middle of a Necron battlefield, with swarms of Canoptek Scarabs bearing on her forces, she only has the time to see Taylor descend and turn the tides of the battle before expressing It Has Been an Honor and finally passing out.
- Omegon comes to see the Emperor of Mankind in the Oneiric Realm, seeking protection from Malal's encroaching influence. The Emperor agrees - on the condition that Omegon fully submits. Omegon briefly considers... and refuses because, after the Heresy, he no longer trusts his father. The Primarch of the Alpha Legion is under direct threat of Chaos, and he still rejects the Emperor's offer because he doesn't feel safe around his own progenitor. Ouch.
- After defeating Iash'uddra's shard in the Throne of Oblivion, Taylor is forced to watch as the Sanguinor (who just sacrificed himself to save her life) and the Second Primarch (who had been possessed by Iash'uddra and kept alive ever since the Second Legion's attack) die in front of her, barely having the time for a few words and requests before they expire. And that's on top of her losing three members of the Dawnbreaker Guard, all of whom she regarded as her friends.
- 10-5 opens with the Emperor alone in his psychic realm, having sent the Custodes away so they won't see him cry for his son's death. Even if he knew intellectually that Hanzo was going to die and even though the Emperor was able to save his soul, it still hurts just as much as all the other friends, loved ones, and dreams he's lost.Sacrifice. It's always about Sacrifice... and surviving to see your dreams turn to ash.
- Traitor Marines they may be, First Harrowmaster Gonzaga's final moments are still heartwrenching. After the Beta is boarded by Tyranids, he commands Phocron to fire on the battleship, because letting it fall in anyone's hands is too disastrous to let happen and the Tyranids are simply too strong even for them. Phocron, revealed to be Mathias Herzog, former Captain of the 2nd Company, is forced to perform a Mercy Kill on his own superior and gene-brothers.
- The surviving Primarchs' reaction when they learn what happened to Hanzo. Magnus actually looks ready to cry when Weaver gives him a book detailing the fate of the Second Legion.
- The realisation that Perturabo and Hanzo were the best of friends is this as well, especially with the subsequent reveal of Perturabo's utterly unemotional reaction to Hanzo's death in the present, showing just how far the Lord of Iron has fallen.
- The butcher's bill for Stalingrad and Macragge is even worse than Commorragh. 49 million Guardsmen, 54 million Skitarri, 8,274 Astartes, 931 naval vessels of various classes, 10,155 aircraft, 80 Titans, and 220 Knights. And that only counts those who fell under while under Weaver's command. It gets higher when you add in those who fought under Valens and Trevayne's commands. And the civilian casualties, which were in the billions.
- Liandra of Caldor's insistance on Weaver bestowing immortality upon Wei Cao and Marianne Gutenberg becomes quietly heartwrenching when the Eldar bluntly admits the Living Saint will have to face eternity alone if she doesn't pick someone to share it, and it will drive her mad from loneliness. As it did to so many people — and that is the reason behind the Queen of Blades taking another Apprentice in spite of being cruelly disappointed by the previous one. Even bad company is better than none at all.
