We can summon only 6 cards with it.
Alliance: Darkforge, Elven warlock, Princess of elves.
Runic: Dwarven elder, Dwarven fortress, Mountain king.
These cards are powerful by no means, but very situational (except Princess of elves, but if you got, say, Crugg the Destroyer or Forest Dragon after it - you won't be happy). Dwarven elder, Darkforge, Elven warlock need high facilities, Mountain king needs attack on you, Dwarven fortress sets your tower to 40.
I'd say in this case condition should be >7 or even >6, considering its cost.