In a singleton format you have to run a set of cards that all fulfill the same basic function, so instead of running 4 copies of Harmonize, you might run Harmonize, Greater Good, Beast Whisperer, Return of the Wildspeaker, Garruk, Primal Hunter, Shamanic Revelation, Soul's Majesty and Rishkar's Expertise
You'll only have at most 1-2 turns to change the outcome of the game
It can be used when the opponent wants to go for a lethal kill by saving your creatures and using this spell while also developing your board
Graded Population Report: Plusle #33 Visualize the distrbution of grades in the chart
Amethyst cards focus on magic abilities and effects, with perks like drawing extra cards or exerting opponent Glimmers
The first one that comes to mind is Klauth, Unrivaled Ancient, who will help generate even more mana