Mass Suggestion is on the bard spell list, so I don't see much competition. I do see competition from other fun/flavorful spells not on the bard list, though!Bones of earth is permanent (no concentration). Good for standing on, and walling things off. Maybe use down time to make a maze. Though it competes with mass suggestion.
Indeed. Even though you're likely to take Wish, which you could use to do Illusory Dragon, you could also take Illusory Dragon and be able to create 2 per day with your level 9 & 8 slots! Then again, Prismatic Wall is pretty strong.Illusory Dragon is solid, paticularly with the weaker level 8 spells.