4 Oct 2004
Can be used on a creature that is already tapped.
19 Mar 2021
If an attacking creature has multiple evasion abilities, such as shadow and flying, a creature can block it only if that creature satisfies all of the appropriate evasion abilities.
19 Mar 2021
Multiple instances of shadow on the same creature are redundant.
19 Mar 2021
Once a creature has been blocked, that creature remains blocked and will deal and be dealt combat damage even if it gains or loses shadow or if the blocking creature gains or loses shadow.