There are many cards that increase mana and gem matches that are quite popular.
{{pageTitle}} | mtgpq.info = rare support = At the beginning of your turn, gain 3 mana. Activate 3: The first colorless card in your hand gains 2 mana
{{pageTitle}} | mtgpq.info = rare support = At the beginning of your turn, gain 3 mana. Landfall: If this Support was Destroyed this game, Return it to the battlefield.
{{pageTitle}} | mtgpq.info = rare support = convert 2 gems to your PW color
also various color bound supports & spells.
I propose a series of cards that increase the Loyalty attribute & gems:
uncommon colorless support = gain 1 loyalty at start of turn
uncommon colorless support = convert 1 enemy gem to loyalty (Loyalty Gems are neutral not colored)
rare colorless support = gain 2 loyalty
rare colorless support = convert 2 enemy gems to loyalty gems
mythic colorless support = gain 3 loyalty
mythic colorless support = convert 3 enemy gems to loyalty gems
masterpiece support = gain 4 loyalty
masterpiece support = convert 4 enemy gems to loyalty gems
I expect these cards to be popular and increase the value of PW powers.