His greatest mistake

Batman has recruited many individuals, Dick Grayson became something better, Jason Todd was his greatest failure, Tim Drake is a prodigy in his eyes, Barbara Gordon is someone he admits can fully trust and believe in, Cassandra Cain has become everything he always wanted her to be and the list just continue with Spoiler, Batwoman, Batwing and of course his son Damian Wayne, but what if I told you there's still one partner that only a few people know about. He was the best, he was skilled, he was brave, he was feared and he was like Bruce which labeled him to become Bruce's greatest mistake

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