Can Wildclaw Shaman immediately use the buff that Cithria Cloudfield gets from playing another unit (the Shaman itself) to ready Wildclaw?

Ruling: Yes, Wildclaw Shaman can immediately use the buff that Cithria Cloudfield gains from Shaman being played to ready itself. This works even if Cithria already had a buff before Shaman was played.

Sequence:

• Wildclaw Shaman is played
• Both effects trigger: Cithria's ability to gain a buff when a unit is played, and Shaman's ability to spend a buff to ready
• You choose which effect resolves first in non-showdown scenarios
• Cithria gains a buff from Shaman being played
• Shaman spends that buff to ready itself

Nuances:

• A unit can only have one buff at a time, but can be buffed multiple times (new buffs replace old ones)
• If Cithria already has a buff when Shaman is played, Shaman can spend that pre-existing buff, and then Cithria can gain a new buff from Shaman being played
• Cithria's parenthetical effect ensures she gets +1 power permanently if she doesn't have a buff when gaining one, even if that buff is spent immediately