Why are you still asking stupid questions, shield hero? How long is it going to take you to realize that he does things for a good reason? Not going to grow up at any point, now are you, shield "hero"...
Tact is a reincarnator who ends up killing all of the 7 Star Heroes of their world and stealing their weapons. He kills a lot of Naofumi's closest allies and was the cause of a bunch of problems. Motoyasu couldn't remember because if he did, he'd almost immediately kill him in revenge for what he did in the main timeline.
@SifDoge No but it also helps with that. The reason for the blurred face is because of time traveling side effects, but it is convenient for the manga to be able to hide a character that hasn't been introduced yet in main story line.
He is one of the antagonists for the series. His personality is basically all the bad points of the heroes put together. He goes around killing the 7 heroes and taking their weapons believing only he is worthy enough to have the weapons. He is responsible the death of 5 of the 7 heroes, The Queen of Melomarc, Atla, Thousands in the Alliance Army, and a portion of Naofumi's Villagers.
Let me guess: The whip hero is a isekai'd person.... plz tell me I'm wrong, the people from that world are shit enough to make this a believable scenario without that...