To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of Serah Farron or Crystallized Serah's first abilities)
Checklist How early does your ramp work: Two-mana ramp is glue
One "ping" from Oliva can reduce any Eternal Witness or Snapcaster Mage to a memory, rather than a card
Lore is essentially a victory point, with the goal of Lorcana being to reach 20 before the opponent to secure the win, so having four Lore is nothing to sneeze at
Especially if you end up filling your deck with effects like Lilianas Caress
We've got them here: White, Blue, Red, Green