Eidolon of Astral Winds
Enchantment Creature — Spirit
Oracle Text
Vigilance
Constellation — Whenever this creature or another enchantment you control enters, choose target creature you control. Until end of turn, that creature has base power and toughness 4/4 and gains flying.
Watch Out
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.
This card's ability triggers when it enters the battlefield, not when it's cast. Effects that double ETB triggers (like Panharmonicon) work here. Countering the spell prevents the creature from entering, so the ETB won't fire.