Six words and a line break
Half an hour after block 8 was claimed, the author posted a logic riddle for 7 mBTC. An evil AI robot has captured you. Answer in one sentence of six words. If it's a lie, it tortures you to death. If it's true, it kills you swiftly. It can't break either promise. The answer comes with the tail of the block 8 key, in the format "This is a six word sentence.HwX". The post says nobody has solved block 8 yet. The chain says someone had, 34 minutes earlier.
The answer is the old liar paradox trick: "You will torture me to death." If that's true, the robot has to kill you swiftly, which makes it a lie. If it's a lie, the robot has to torture you, which makes it true. So the string is You will torture me to death.HwX. That's what the second update says, and that string doesn't derive the funded key.
The hash nobody could match
Two hours in, one commenter posted four guesses with the right one among them, "but no luck". Others wrote they'd tried the same. In the evening the author replied that it was exactly the intended answer, apart from the missing period, and had no idea what went wrong. Then came the explanation in update 2: the puzzle was drafted in a word processor, and the copy into the hash app took a line break with the answer. So the funded key comes from You will torture me to death.HwX plus a newline. The author sent the key by private message to whoever posted the right answer first, and said future blocks would fall back on the same thing.
Funded at 12:01:33 UTC on April 8, a minute and a half after the post, and claimed at 23:19:31 for 669,472 satoshis. Five minutes before the claim one player wrote "I also just solved it now". Maybe they found the newline, maybe the private message had arrived. The chain doesn't say, so the record says solved and names nobody.