The bottom line is that you wont want all your card draw in only one of the colors in a typical multicolor EDH deck, so finding a few red draw staples helps make your decks more consistent
3(T): Sacrifice Vitality Vigor, target creature gains indestructible until the end of turn
While one less damage is big, it never hurts to have multiple of the same effect, and allows you to get more consistency
Among the sub-themes, we can point out a focus on high Willpower characters, since they survive many Challenges throughout the game, and a direct Lore gain through Challenges - which means that, in this decks, Challenges not only help with board control but also become your win condition
Having previously led the vision design for Bloomburrow , his designer hat came in handy for exploring resonant and more "out there" mechanics involving exploring the House of Horror