Cabal- im not scared of these. They are too much like humanity's own imperialistic side. They are only out to conquer and expand, which I don't find terrifying. They aren't very intelligent compared to the other races either. Vex- these are really terrifying conceptually, but not up close. They are powerful and foreign, which is scary, but they are also interesting and, if only foot soldiers, not even overwhelming Hive- I find the hive the scariest by far. They work without normal technology, relying on some methods guardians consider dark magic. That alone shows how otherworldly they are. They are also sadistic, stripping flesh and light from guardians for pleasure and study. They have claws, are very foreign in appearance, and are completely different from humans. They are also arguably more evil than all of the other races. Aesthetically they also have an edge on fear Fallen- I consider them bros, tbh. Some of them are good, and I think they are very much like human beings. They are enterprising, once held the traveller, and they are clinging on to lost power and nobility, just like the human race in destiny. Despite them not having a sustained fleet like the Cabal or unlimited power like the hive or vex, they manage to be a huge problem and are thus far the only race that has actually almost successfully taken the city. I like the fallen, especially because they seem to have so much spirit, and so many emotions and feelings similar to humans. If you read the grimore, you'll see a female vandal hold off against hive with Cayde 6, and then pretend to Attack him in order to die in battle. This shows a kind of cumulative exhaustion on this fallen, her giving in. This is interesting. They are not really a lost race- they are trying to reclaim what they lost. They might have fallen a little bit, as their name would suggest, but they aren't outright evil and they have a lot of potential. I see them as what we could have become after the collapse.