Okay so I've been rereading this series and i have a theory that nearly everything in this world relies on luck bc i assume the reason that haruka gets all these skills is bc of his max luck, so its like a luck roll whether u aquire it so he always aquires it and the prez's plunder skill is also on a luck roll whether or not she'll plunder a skill from a kill. Otherwise why has prez not gain a skill using plunder until now bc shes definitely been killing monsters so.