Weapon card becoming a creature? [Not a bug]

[segi]

I just saw a Morning Light (or is it Morning Star? I mean the rare Light weapon that's not found in the Bazaar), which is supposed to be a weapon, become a creature instead. It was played from the level 1 AI's hand. After that, it hit my Skull Shield and became a Skeleton (which retained the 'invulnerable' status) - so, not that I'm complaining in this case since it was to my advantage, but it really looks like it's not supposed to happen. Don't know if that matters, but the AI's element was aether and mine was darkness.

[XYTWO]

The AI probably played Flying Weapon, which is an Air spell that turns the user's weapon into a creature.

[segi]

Ah, I wasn't sure if it would still work with an immaterial weapon - but I guess it does. Thanks.

[Chromatophore]

Ah, I wasn't sure if it would still work with an immaterial weapon - but I guess it does. Thanks.

Yes immaterial weapons are untargetable, but the flying weapon spell does not need to be targeted.  (You cannot animate your opponent's weapon for example)  Effects which take weapon targets like crusader's endow could not target morningstar.