If you have to censor your words, maybe don't say them in the first place.
Also, it's a helmet plume, they're common on medieval and Greco-Roman helmets.
In any case, you can still obtain the items you want. Or, alternatively, don't advance to 5-star rank, unless you really want the 15-star scroll.
If the issue is resolved by using a rune, then this is intentional behavior.
If you leave a run inactive for too long (about 5 minutes), the rune will trigger a curse that starts to lower the EXP and drop rates of the mobs in the map, depending on how long the rune has been left unactivated (maximum Stage 4, 100% EXP/Drop reduction). It should also display this information at the top of the screen:
Using a rune will remove the curse on the map, and grant you 15 minutes of immunity to the curse.
Invincibility does not stack infinitely. You can only have a maximum number of seconds of invincibility before the effect reaches a cap.
Amaterasu's Death Bringer weapon is dropped by the Ranmaru boss, as is Amaterasu's Helm (both the recipe and the equips directly drop from Ranmaru). Normal Ranmaru is level 129 and Madman Ranmaru is level 195, you can locate the boss by going to the map Dead Mine III in El Nath and speaking with Tokugawa Ieyasu.
The helmet can also be obtained from the Eyeful's Armor Coupon that drops from the Julieta boss in Monad, but you must complete the Monad blockbuster to battle her.
Prepaid is available in stores as a physical card, or available on certain game currency sites such as PC Game Supply, Offgamers, or PayPal. Purchase the cards labeled "Karma Koin".
