Reading the January 2010 rules update I came across the following:
QUOTE:
Dark Depths
The Marit Lage token that this card creates is inherently legendary, is inherently black, and inherently has flying, because all of those are characteristics. If you copy the token with Sakashima the Impostor, for example, Sakashima will gain those characteristics too. However, being indestructible isn't a characteristic; it's just something true about the token. That Sakashima will not be indestructible. This is wildly counterintuitive, especially since the Marit Lage tokens we printed to go along with Dark Depths say "This creature is indestructible" right on them! The determination is that this functionality loophole is an unintended oversight, and it's being corrected.
New wording
Dark Depths enters the battlefield with ten ice counters on it.
{o3}: Remove an ice counter from Dark Depths.
When Dark Depths has no ice counters on it, sacrifice it. If you do, put a legendary 20/20 black Avatar creature token with flying and "This creature is indestructible" named Marit Lage onto the battlefield.
Now to me the new wording is no less counter-intuitive than the original, and I don't really understand what makes something a characteristic. Here's the definition:
QUOTE:
109.3. An object’s characteristics are name, mana cost, color, card type, subtype, supertype, expansion symbol, rules text, abilities, power, toughness, loyalty, hand modifier, and life modifier. Objects can have some or all of these characteristics. Any other information about an object isn’t a characteristic. For example, characteristics don’t include whether a permanent is tapped, a spell’s target, an object’s owner or controller, what an Aura enchants, and so on.
I have highlighted abilities, because characteristics include abilities. The rules give an example
QUOTE:
"Example: “[This creature] can’t block” is an ability.
Can anyone explain to me why "This creature is indestructible" is not an ability and therefore copyable?