While attuned to this cloak, you can breathe underwater when you put the hood on, and tentacles coming out from it propels you, giving you a swim speed of 30 feet.
Ink Cloud. Once per short rest, you can use your bonus action to create a cloud of ink-looking darkness in a 5 feet radius around you as per place the spell Darkness. This cloud stays in place and disappears at the beginning of your next turn.
Writhing Touch. Tentacles increase your reach for melee spell attacks with a touch range to 15 feet. Additionally, you can summon a tentacle from under the cape and use it to attack. Make a melee spell attack using your spell casting ability. It inflicts 1D6 bludgeoning damage. You can summon and make an attack with an additional tentacle at levels 5, 11 and 17. For each successful attack , a Huge or smaller target has its speed reduced by 5 feet and suffers a minus 1 penalty to Strength and Dexterity skill checks and saving throws until the start of your next turn, as long as you stay within range.
Depths Grasp. You can cast Maximillian’s Earthen Grasp and Grasping Vine without expending a spell slot, shaped as tentacles. Once you’ve cast either of these spells in this way, you can’t do so again until you finish a long rest.