The fact that Omen shuffles back in is very relevant since this can grab a basic out of the library AND also be a creature in the library for the purposes of Lotleth Giant
It works best in conjunction with shuffle effects, as those empower you to get rid of cards you don't wish to draw, and of course with cards that let you play from the top of your library
But most of the time, we use it to rest one of the opponents blockers, making sure we can hit their Leader without any blockers getting in the way.
Paired with healing or resist, she can do some work
We then see a shift to level 4 and 5 where 4 is everything is allowed and 5 is a shift to a competitive mindset and a focus on competitive metagame
It makes a huge difference in how you play your cards, especially if you play multi-colored decks since you can run out of a specific mana type quickly if you dont manage your sequencing properly