Chaos Orb destroys any cards that it touches when it lands, whereas Falling Star deals 3 damage to any creatures it touches when it lands (and also taps them) and has no effect on non-creature cards
SAPPHIRE & STEEL JUDY HOPPS & ROBIN HOOD
In Obeka, the Sphinx is a body and triggers your upkeep effects one more time before the end of turn and untaps your board
While it can take a bit of work to make a burn theme work in an Aegar deck, the extra card draw is hard to pass up, especially in an archetype that can sometimes struggle to provide it
Outside of perhaps the alternate commander Sophia, Dogged Detective, you can play with Deep Clue Sea as-is and be able to hold your own against many other decks
This card can easily patch up any holes in a green decks strategy, allowing you to field huge threats each turn while keeping your hand fully restocked with each play