3 Flubs, the Fool Fumbles His Way to Victory A High-Powered Hellbent General Flubs the Fool is unique in modern Magic design for a few reasons, but the most striking one is that Flubs was printed with an actual downside: Whenever Flubs' controller plays a land or casts a spell, they must discard a card unless they are completely hellbent or hand-less
Light allows UW to answer troublesome permanents like Esikas Chariot, Meathook Massacre, or The Celestus without needing to sweep the entire board with Mastery or (now) Farewell
In short, you want to balance the mana value of your spells to ensure you have effective spells to cast throughout the game
Faerie Swarm could be a huge creature for only 4 mana if you can manage to get a lot of small blue faeries or other blue permanents onto the board
The biggest thing to learn are which abilities you can trigger so here are a few great examples of allies with text that includes when, whenever, and at: Katara, Bending Prodigy, South Pole Voyager, Ondu Cleric, Earth Kingdom General, and Hero of Goma Fada
We wouldn't want these scientists-turned-gods, seen through a Magic: The Gathering lens as "God Artificers" staring down or up from a table at us