Captain Tyvar did what a Custodes should do. Still feels like a shame, but he had enough evidence and the Brazen Drakes gave enough resistance to justify it.
The Brazen Drakes were acting like fools, though I can't help but imagine that the hyper cautious approach of the Custodes makes them extremely vulnerable to false information fed via infiltrators. We know that the Alpha Legion have and do impersonate Inquisitors all the time. They can very easily frame dozens of chapters and even Guard armies or even just make them look slightly suspicious, and that can be all that's needed to completely wipe them out. I kind of wish this story ended with the non-primaris Brazen Drakes being cleared of suspicion to add to the grim dark atmosphere.
Anything done by the Alpha Legion at this point always feels like a mystery. They can so easily be acting for either side. I still like to hope they are mostly Loyalist. I also would have loved to have seen that the FIrst Born were actually innocent. Would have been perfectly Grimdark, as you say.
I'd love a story on: A.) The creation, deeds, campaigns, betrayal, and tragedy of the Thunder Warriors. B.) The Men of Iron and UR-025... or the STC's. C.) Pre-Imperium Old Earth. D.) Dark Age of Technology/Golden Age of Technology. E.) Did the Emperor plan the fall of the Golden Age of Man by his machinations by instigating a shadow war to incite the Men of Iron during the Dark/Golden Age of Technology; allowing the Old Earth to break down with discord, famine, disease, while the world boiled off the atmosphere, unwittingly permitting the losing of the mighty STC's, allow it to get just bad enough, ripe for the picking, only to "assume" the mantle of leader throughout the Unification Wars, (Remember he was a Tchno Barbarian Warlord too... He just was the one who Won.) only to aid himself into his own vast dominion and self-induced god-hood. (Seems pretty sus for a non believer‽ 🤔)
I love all these suggestions, and full disclosure, I have actually been working on a Thunder Warrior themed video. Though it might be a little while before I am able to make it. I'll be moving to Canada from the UK soon, so unfortunately I have to divide my time up away from RU-vid stuff until things have settled. But hopefully will release something soon after that! Options E, would be a massive undertaking, and one I would love to talk about. If I do get around to making a video like that, I'll be sure to credit your comment as inspiration!
Before the Horus Heresy and relgious zeal took over, I would have agreed with you. Though I am certain somewhere that Astartes are stated to swear their loyaltiy to the Emperor, even during 30k. The only decent bit of evidence I can find is from Dark Angel books, where Nemiel refuses to follow Lion El'Jonsons orders. "I have issued an order, Brother-Redemptor,' said the Lion, drawing himself up to his full height. 'One that I cannot follow,' said Nemiel, his tone hard, trembling with the effort of defying his primarch. 'My authority is absolute,' the Lion said, clenching his fists, his lips drawn back to reveal gleaming teeth. 'The Edict of Nikaea was issued by the Emperor, my liege,' said Nemiel 'There is no higher authority." It's not the best, but it is the freshest in my mind as that is what I have most recently been reading. Now as for this scenario, and 40k in general. The Emperor is 100% the authority, loyalty is sworn to The God Emperor of Mankind. Anythng less is heresy, even more so infront of a Custodies.
