I try to design each single color to be good on its own as much as possible.
White: Horizontal Strategy & Sun Titan Recursion
Blue: Counter & Card Selection
Black: Reanimation & Spot Removal
Red: Burn, Haste, Recursion
Green: Creature Tutor & Ramp
LANDS
Lands are mainly duals with basic land types for each guild except the one with manland. The reason of this is to push green ramp potential Farseek, Sylvan Ranger. I also include 5 Ikoria triple lands to push more splashability (small cube, less option in single color).
NOTES
I purposefully didn't include narrow cards like Goblin Guide which only playable in aggro, because in this small cube, I try to be as versatile as possible. This makes my cube doesn't support aggro too much.
I kind of hesitant to include cards like Faithless Looting and Gifts Ungiven right now. Because they push reanimation strategy more compared to contributing their own color goal.