Supposedly, the Demotank's taunt is supposed to be better because he's super durable less often. The Demo is supposed to be relying wholly on shields rather than just facetanking forever (and even then, he's got Nanoshield to instaheal him to full). The Assault, on the other hand, can effectively facetank forever and stuff his face with kits and bandages and is effectively invulnerable with a barely competent Medic. This is why I want to nerf Time to Die, so the Demo will actually be forced to rely on shields all the time. In NOTD 2, the taunts will actually be very different. More bosses will have castable attacks and other abilities. IYF will force enemies and bosses to target the Demolitions, which involves still using skills. This can very easily lead to disaster because, well, some of those abilities hit very hard. Taunt, on the other hand, will interrupt abilities and force direct attacking.