The likes of Waste Not, Harmonic Prodigy and Jeskas Will can help you get Kefka flipped quicker, by adding mana and doubling up on hand attack
An important thing to note is that Limited archetypes are just recommendations for the kind of deck to build with those colors, but not necessarily a requirement
Lyle does have a high ink cost of 8 but grants 3 Lore points when questing and has stats of 6 Strength and 4 Willpower, so he's a very valuable card
The two starter decks are a simple way to start playing, with a pre-made 60-card deck, plus an added booster pack for your first pulls
Overall, Amethyst, Ruby, and Steel are more focused on attacking while Amber, Emerald, and Sapphire are more supportive, but each can be used to make interesting combinations and people can experiment with seeing what strategies work with their personal play style