In my opinion, what the "Armor Mission" part should give is Optional Threads Pack instead of straight up giving Common or Medium Threads for the sake of all kinds of players (From Old to New) ..

The Medium Thread note in the Ninja Handbook feature seems to be a Visual Bug but if not then probably they changed the Pack .. But the problem is, they changed it without realizing that they made a mistake .. Some people will say for sure that this Pack or Feature is intended for the New Players of the Game or some other peoples will care less for what it gives but for majority of people who plays the game for free .. That massive amount of free stuff is a big help .. So what's wrong for giving a 50pcs Common Thread? Well, the only way to accomplish that mission is to Level up your Armor to 3 and Upgrade the Rank of your Armor to 3 which contradicts to the Reward that you will get .. Common Threads are only used for upgrading your armor from 1 to 3 and after that, you'll be needing Medium Threads .. Now if this is intended for new players then the total context of giving a 50 pcs of Common Threads will be non-sense thus this pack will be useless for anyone in the game ..

Now if they revert it back and the pack will now give 50 Medium Threads then maybe it will be acceptable for those players who are still at the process of upgrading their Armor using Medium Threads and we, the players who are at the process of upgrading using Advance Threads will understand the context of this Event that it targets new players .. But it is much better if the pack will be Optional for the sake of all players ..

Another thing about this Ninja Handbook is the bugged Magatama Packs which contains Awakening Items .. Hope this things gets fixed and get done .. Don't make your players feel they're irrelevant to the game since we are only a free players ..