Normally, the Set Rotation would ensure that Singing Mermaid would not be legal/recognized for use in Core Constructed tournaments
That being said, items are clearly getting a further boost as a strategy in Into the Inklands, and this card only furthers the viability of that strategy
Robin Hood, Unrivaled Archer has a resource cost of 6, attack power of 4 and a defense raiting of 4
Alphinaud Leveilleur* 4 Mana for Alphinaud is a lot, given what else you can get in card draw there, and the fact its only on your second spell each turn combined with a poor size make this a creature you probably leave out of your party, unless you are wanting to make use of its partner
The set features cards taken from every mainline Final Fantasy title, including the two MMOs, so theres something for every generation of Final Fantasy lovers