it is harmless filler equipment, it is a sacrifice outlet and it is a pinger
While bouncing three creatures isn't great for five mana, countering a spell isn't great for five mana, and drawing three cards is only okay at five mana, the fact that you can do things like counter a spell and draw two cards, bounce a creature and draw two cards, or bounce two creatures and counter a spell makes it so the sum of Mystic Confluence is much more powerful than its individual parts
Six Mills and lets you retrace a card you accidentally pitch to the graveyard
Enter intense battles of titanic proportions with an army of magical mechs
Rather than opening one only when she enters the field, she allows the player to open an attraction after each and every instant and sorcery cast from the hand
Lastly, Abhorrent Oculus offers manifest dread as a long-term value engine