Actually, when I was testing them early on, they were very weak when they appeared in my opening hand, and there were many situations where I would attack and draw a ton of cards, but didn't have the mana to spare to cast an extra turn spell
If an opponent is at 40 life, and takes a hit from Astarion with the Spike equipped, they will lose four life from combat damage, putting them to 36, and then half of that from Quietus Spike, dropping them to 18, for a total of 22 points of life lost
For over a year control decks got to be at or near the top of Standard, and without Mirari's Wake it is doubtful they would have seen much play at all
It might not work at high power levels where your threats need more than stats, but Ive played many Cubes that might be interested in this
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