Just curious, why do you say it will replace the Hanzo challenge? Now that we know how to beat it that makes sense, but I figured maybe they'd keep both around for players without enough common thread.

I'm in the same boat as you; I knew that this event was coming from a tip from a friend around a week ago, maybe more, so I saves all the common thread I won to upgrade once the event came. I got impatient though and used it all, like, a few days ago T_T. At the rate it takes to upgrade it's impossible to get more than one rebate and for some to get any rebates without paying. Whether that was the strategy of this event or not, it's still...