I have a theory about specifically what Kabr meant when he says that he "I drank of them. It tasted like the sea." As I think many people would assume, you think he was talking about the oracles, however I don't think that this is the case. I think he is literally talking about drinking the Vex themselves. As many don't know, the Vex are actually Radiolarians, which are zooplankton and are found throughout the ocean. Radiolarians are known for the siliceous ooze on the ocean floor. So when we kill a Vex with a precision shot, it splatters ooze all over the ground, and since radiolarians are found in the ocean, if Kabr and his fireteam "drank of them" and they are radiolarians it would make sense that they tasted like the sea, as the liquid inside a vex would probably be similar. If Kabr was wearing Vex armor to try to blend into the Vex network, or at least with the vex, then would it not be plausible for him to have drank the Vex to try to be seen as one or access the network. This drinking could also explain how Kabr was "infected" by the vex, alongside the armor. According to the new grimoire card, Vex 4, it tells of how Dr. Shim and his team from the Ishtar Collective are going into the Vex citadel on Venus inside of proxy bodies. They cannot set foot inside the citadel in their actual bodies because "The cellular Vex elements are infectious, hallucinogenic, entheogenic. The informational Vex elements are more dangerous yet - and there could be semiotic hazards beyond them, aggressive ideas, Vex who exist without a substrate." So if entering the Vex citadel on Venus is infectious, can cause hallucinations and can literally implant aggressive thoughts into someone without actually having a Vex substrate present, what do you think would happen to Kabr after he drank them, and wore them as armor. This would explain why he says that "If I speak again I am not Kabr." The theory that Kabr and possibly members of his fireteam drank the Vex is supported by a ship added into the Destiny database with the release of the HoW, named Alemyrs lament, it is a vault of glass ship, with the description "Would that I had stopped him before he drank." I think after drinking the Vex Kabr knew that he was at least being influenced by them, so he used his light to create the Aegis for future guardians.