1)The lost are previous heros who lost to dragon. They are ghosts that float in distance of the islands, when you get to 7 blocks closeness, the go invisable, the only way to get close is a pumpkin, and they drop spirit husks which makes you invisable for 10 seconds unless you take damage, but it takes one or two hunger bars . The can throw enderman into the void.
2)Endergrasp are jellyfish like with barbed vines and can be rid without taming or saddles. they are passive but when hit they can grab dropped items and throw them in the void , or even the player, they cry and laugh when hit, they live in the chorus region and love to eat chorus fruit and then drop forgotten veil . When eaten, which heals you and gives temporarily full armor made of spirit, will make you have bright spots around screen with a sad melody.
3)when you use disk 11 with 3 forgotten veil and 3 spirit husks make the "heroes elegy" disk which is a sad song with army marching sounds and crying .