If contradictions are common then you really have no arguments against the Blood Ravens, since your entire problem with them is that they don't fit into the lore. Aside from the fact that Graham McNeil wrote about them in Forge World, they've been embraced by Games Workshop, and subsequent books have hinted at their relationship with the Thousand Sons, of course. But like you said, contradictions are everywhere in Wh40k. Better to stop caring about inconsistencies
There's a difference between minor contradictions and those that do not represent the fluff at all. This is why the stringent community following W40K loathes most of Relic's work for being terrible representation of the fluff and the Blood Ravens being near impossible to fit. Even with consistences- they should be a renegade chapter which the Inquisition is constantly trying to put down. The Blood Ravens however are more heretical than the Black Dragons and Space Sharks, who are already closely watched for heresy. Hell, at this point, any Chapter without their Gary/Mary sue level of plotshields, would likely have the High Lords of Terra sic the Minotaurs on the Blood Ravens chapter for extermination for heresy and thievery. They're affront to the fluff and deserve to be killed off more than the Squats. (That and the fluff operates is that everything is true and everything is also full of lies. Contradictions are seen thus seen as more untrue. So either the Blood Ravens have a conspiracy going on trying to hide their heresy, data corruption, or are trying to be shown as evil by the Inquisition by inflating their heretical actions.)
The fluff about it changes depending on where you look. It definitely used to be that they weren't all psychic, now they seem to all be psykers to at least some degree. The only link between the two I took with any seriousness was in the 1000 sons book, where they talk about a blood raven (I forget the actual quote, lol).
You've yet to express WHY you think they're heretical Mary Sues, but there you go. Also, here's a quote from A Thousand Sons I think you'd like very much: "“It’s too late… the Wolf is at the door and it hungers for blood. Oh, Throne… no, the blood! The Ravens, I see them too. The lost sons and a Raven of blood. They cry out for salvation and knowledge, but it is denied! A brother betrayed, a brother murdered. The worst mistake for the noblest reason! It cannot happen, but it must!"
But the inquisition IS keeping a close eye on the Blood Ravens. Like they are keeping a close eye on freakingeverybody. I dont find them to be that lore breaking than you do. Dont take their ingame stuff as canon though, like some gameplay mechanics, ie relics from different chapters. They are not my favourite chapter though. I like them, but a lot of other cooler chapters out there. If there were a game with Minotaurs as protagonists, wiping out Blood Ravens, fuck yeah, since those lovable guys are my absolute favourite. Otherwise, leave them be. They are definitely not the worst with heresy
Because they've stolen numerous holy relics that certainly weren't gifts (the HLoT don't hand out Custodes armor like candy), and the entire events of the DOW games would have normally resulted in them being all declared traitors. Their former Chapter Master was a Chaos Lord and later elevated to the level of a Daemon Prince of Khorne, the chapter was manipulated by a Chaos Lord/Daemon Prince for a long period of time, one of their greatest champions was his puppet, numerous Blood Ravens fell to Chaos and resulted in a clusterfuck of a civil war within the chapter that nearly tore themselves apart thanks to Chaos taint. Even their new Chapter Master, Angelos, was the person who (accidentally) started the heresy within the Blood Ravens and unleashed a daemon. Mind you, simply coming into contact with one daemonic enemy or disease like Doubtworm is enough to make the Inquisition wary. The Blood Ravens were riddled with heresy and either should be dissolved or carefully watched by the Inquisition with other Chapters being quite cautious around them. Rule-wise, they should have ended up something similar to the Black Dragons, only worse, and unable to ally with other Imperium forces/them likely abandoning them in battle.
How can you not like them? They are pretty much everything the other space marine chapters are not. I just adore their whole idealogy and way of being. And their looks. If Blood Ravens had to go for them to have a go at being in a video game, it would be glorius.
The relics in the games are obviously a game mechanic and nothing more. They didn't literally steal those.
Strangley I can imagine the future of the blood ravens nearly ending up like the legion of the damned. They get destroyed from within, and they become a rouge chapter, only to be seen on very rare occasions (or not at all) fighting chaos, but not answering to the imperium.
