Tyco's Two-Step

Upon casting, a second version of the caster appears in a place that they are familiar with in the same plane of existence within 60 feet at the same time. In one of those places (of the caster's choosing), the caster is incorporeal (though they appear solid to others).

Within the duration, the caster may take a bonus action to change which existence is incorporeal. The two existences move as one in lockstep. When the caster attacks, the incorporeal existence does no damage. If either existence is attacked, the caster must make a CON saving throw to maintain concentration. When the spell ends, the incorporeal existence disappears.