Echoing simulacrum

You weave an illusion of shimmering light that solidifies into a perfect, semi-real duplicate of yourself. This duplicate shares your appearance, Armor Class, and hit point pool. Damage taken by either you or the duplicate is subtracted from this shared pool. If the shared hit points are reduced to 0, both you and the duplicate fall unconscious, and the spell ends. The duplicate appears in an unoccupied space you can see within 30 feet of you.

The duplicate is under your control and shares your turn. On your turn, you can take your actions, bonus actions, and movement from either your own space or the duplicate's space—as if you were physically in that location—but you cannot act from both locations on the same turn. You can switch which body you are controlling as part of taking an action. You can also freely switch your senses between your own body and the duplicate's as a bonus action on your turn.

The duplicate is physically capable and can take any action you could take, including casting spells (requiring components from its own space) and making attacks. It uses your statistics, spell save DC, and attack bonus. It is, however, clearly magical; a creature can use its action to make an Intelligence (Investigation) check against your spell save DC to determine it is an illusion.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the duration increases: 6th level (4 hours), 7th level (8 hours), 8th level (24 hours). These versions still require concentration. When you cast it using a 9th-level spell slot, the duration becomes Until Dispelled and no longer requires concentration. When cast at 9th level, you can also maintain one additional duplicate from a previous casting of this spell, for a maximum of two active duplicates.