Saheeli, Sublime Artificer

Saheeli's loyalty ability causes the target artifact to copy the printed values of the target permanent, plus any copy effects that have been applied to it. It won't copy counters on that permanent or effects that have changed its power, toughness, types, color, or so on. Notably, it won't copy effects that made the target permanent become a creature.

If the target artifact copies a permanent that's copying something else, it will become whatever the target is copying.

If the target artifact isn't an Equipment and becomes a copy of an Equipment, it'll become unattached when it becomes a non-Equipment artifact again.

If the target artifact becomes a creature the same turn it enters the battlefield, you can't attack with it or use any of its {T} abilities unless it has haste.