You can change the settings at any time (fingerprint icon in the bottom left corner)
During the End Phase of the turn that this card destroyed a monster by battle and sent it to the Graveyard: You can Special Summon 1 "Halloween" Tuner Monster from your Graveyard, and if you do, your opponent draws 1 card
Minwu, Rebellion Strategist (Mangara, the Diplomat) Rating: 5/10 While its very possible to just not attack with two creatures or cast two spells in the same turn, forcing your opponent out of that play pattern is still a worthwhile effect
Instead, select the menu in the top-right corner and tap Clear Cache. This wont delete your save files, so you can use it whenever the game is experiencing issues
Unless Hero tokens get some powerful support cards, this is likely a pack filler at best
Assuming this is true, a banning probably isn't off the table altogether