Once you reach speed 4 youve reached your max speed and now creatures with the ability will get an extra bonus
We also needed something for chocobos to do, and the saddle mechanic didn't exist yet due to the development timelines of Outlaws of Thunder Junction and Aetherdrift
As another example, if my opening hand has a one-drop, a two-drop, a three-drop and four different four-drops, then I will usually bottom the worst three four-drops in the hope of drawing into a powerful five or six-drop, while keeping the cards that will ensure a perfect 1-2-3-4 curve-out
Capsize plus Candelabra of Tawnos plus Tolarian Academy also meant infinite mana
Incredible, Elastigirl, Dash, Violet, and Jack-Jack, arrive as Super glimmers, bringing superhero muscle to the table
For five mana, Kyler, Sigardian Emissary will constantly grow with +1/+1 counters whenever a Human comes into play, and give its power to the rest of your Humans