Aurora Shifter
Creature — Shapeshifter
Oracle Text
Whenever this creature deals combat damage to a player, you get that many {E}.
At the beginning of combat on your turn, you may pay {E}{E}. When you do, this creature becomes a copy of another target creature you control, except it has this ability and "Whenever this creature deals combat damage to a player, you get that many {E}."
Watch Out
Copies don't copy counters, equipment, auras, or other external modifications. A copy of a transformed card copies only the front face. If the copy enters the battlefield, it triggers its own ETB abilities.
This card involves continuous effects applied in layer order. Type changes (layer 4) are applied before ability changes (layer 6) and P/T changes (layer 7). The order matters — a creature that loses abilities in layer 6 can still get new abilities from effects applied later in the same layer.