Again, useful if you want to do tribal bits, although there arent many Elf cards in Red

Sort Card Type Chi-Yu #29Rare $0.14 Chi-Yu #39Uncommon $0.17 Chi-Yu #31Uncommon $0.08 Chi-Yu #25Common $0.13 Chi-Yu #18Uncommon $0.15 Chi-Yu #16Rare $0.72 Chi-Yu #57Rare $0.43 Chi-Yu #59Rare $0.13 Chi-Yu - 029/182 (Non-Holo) #29Rare $0.22 Chi-Yu - 057 (Prerelease) #57Promo $2.62 Chi-Yu - 057 (Prerelease) [Staff] #57Promo $69.51 Chi-Yu (Master Ball Pattern) #25Common $4.68 Chi-Yu (Mirror Foil) #25Common $0.99 Chi-Yu ex #241Hyper Rare $11.95 Chi-Yu ex - 016/071 #16Double Rare $0.38 Chi-Yu ex - 035/190 #35Double Rare $0.25 Chi-Yu ex - 040/193 #40Double Rare $0.73 Chi-Yu ex - 085/071 #85Super Rare $2.10 Chi-Yu ex - 092/071 #92Special Art Rare $43.47 Chi-Yu ex - 234/193 #234Ultra Rare $3.67 Chi-Yu ex - 259/193 #259Special Illustration Rare $56.35 Chi-Yu ex - 356/190 #356Ultra Rare $6.04 Chi-Yu - 057 (Prerelease) [Staff] #57Promo $69.51 Chi-Yu ex - 259/193 #259Special Illustration Rare $56.35 Chi-Yu ex - 092/071 #92Special Art Rare $43.47 Chi-Yu ex #241Hyper Rare $11.95 Chi-Yu ex - 356/190 #356Ultra Rare $6.04 Chi-Yu (Master Ball Pattern) #25Common $4.68 Chi-Yu ex - 234/193 #234Ultra Rare $3.67 Chi-Yu - 057 (Prerelease) #57Promo $2.62 Chi-Yu ex - 085/071 #85Super Rare $2.10 Chi-Yu (Mirror Foil) #25Common $0.99

Given that Merfolk go wide with creatures, a free counter spell at the cost of one lowly Merfolk can be game-saving and/or game-winning
Deeptread Merrow Deeptread Merrow doesnt start with islandwalk, but this isnt as big of a deal as on other creatures
However, if the slab holder can hide it on the left/right of the card then it has a chance to be forgiven
Cards are rested, or turned sideways (which is the same thing as tapping in Magic: The Gathering , exerting in Disney Lorcana , or exhausting in Star Wars Unlimited ) during a turn, when attacking or performing certain actions, and they remain this way until the beginning of your next turn, during the refresh phase