Just so you are aware of the circumstances regarding "taking": Auryx, the King of the Hive, sought to gain the power to feed his worm. This resulted in him traveling to the Ascendant realm in search of Akka. Akka and Auryx spoke of the power of the Deep, and since their power was gifted, and not taken, it was not true to the Deep. Auryx attacked Akka and slew him, then communed with the Deep himself. When he was finished he crafted the Tablets of Ruin, gaining the power to Take and becoming Oryx, the Taken King. Though dead, Akka was not gone, and Oryx was forced to battle his god's "swarming corpse" while escaping his sisters' treachery years later. Oryx used part of Akka's body to craft his Dreadnaught and conceal his ascendant plane from Xivu Arath, the Hive god of War. So yes, the question does remain can a worm be taken. My thought process on it? They can. They thought worm gods couldn't be killed lest their smaller spawn dies with them. That theory was false as Auryx would have died instantly. The condition is simply, "keep your worm fed lest it eats you from the inside." Therefore, there is the reason for an agent not just Savathun to Take once they have the power of the tablets of ruin. The tablets are what is description wise given for the Taking power.