For some CE/IE cards (like Black Lotus or Mox Sapphire) you can identify them by the alignment of the Manacost inside the circle, but this is something which requires possibilities for comparison
That said, this set doesnt really favor three-color decks, and splashing a third color is usually only viable if you're playing greenwhich has slightly better mana fixing
Beyond that, Energy acceleration is usually good
Official Deck Recipes straight from Konami 1 Zubababa Knight 2 Gagaga Ganbara Knight 3 Gogogo Goblindbergh 3 Dodododo Warrior 1 Utopic Onomatopoeia 2 Zubababancho Gagagacoat 1 Gogogo Gigas 1 Dodododwarf Gogogoglove 1 ZS Ascended Sage 3 Ash Blossom & Joyous Spring 2 Maxx C 3 Mulcharmy Fuwalos 2 Gagaga Hope Tactics 2 Onomatopickup 3 Onomatopaira 2 Double or Nothing
Then the latter five-drop 4/3 rare also has our Allies arriving giving the team indestructible for the turn, also good in tons of places, and if you have a flash engine this keeps you alive when foes swing at you or sweep too
It should be noted that this list is a ranking of the Abilities alone, as many things factor into how good a card is, which will not be taken into account here