I don't know if I'd call it "incredibly powerful." It stuns the minions first of all, which means you are only delaying them, not killing them. I've never thought of any situation where I could say "Hey, I really wish I could stun that ONE minion, it'd make all the difference." It's pretty bad. They're trying to paint a turd in gold and call it fancy.
In theory, if you used all 7 "Dream Catchers" on one type of minion, your final stats would look like this, based on the minion:
Melee - 4 Armor, 8 Movespeed
Caster - 4 Mag Resist, 4.8 AD or 8 AP
Siege - 40 HP, 8% Attack Speed
Those are god awful shit stats that you could get from other runes trees at a much higher payout - or hell, even by buying items earlier with Future's Market. Splitting your "dream catchers" between minion types just overall worsens everything, because the sheer low volume of stats you'll be getting from these items is just not enough to make any kind of difference whatsoever. And considering that the item will probably have a lockout like Dematerializers do, this is just a bad rune. They need to stop trying to make fetch happen. This is so bad, and no one is going to be willing to take this rune over the biscuits or Future Market.