Koma offers something different compared to other Simic Legendaries as it cares about interacting in combat, rather than unloading your hand with lands to draw more cards
Hildibrand's adventure fits the requirement, and being an instant means it gets you closer to triggering Y'shtola on other players' turns (Y'shtola triggers on everyone's end step)
Most of the time it will be free though, and it exiles, wont get better than that
If you want to perform a character action that requires exerting the card (questing, challenging, and certain abilities), that card must have been in play since the start of the turn
Other paths to victory might set you on a path to mill your opponents out, while others might combo them into oblivion
Play boosters simplify and satisfy the vast majority of what players want in opening packs