Instead of being a Kamikaze+Cultist, why not turn it into this instead:
- Infectious can only infect killers, using kill button on non-killing roles will kill them instead and if a non-killing impostor-based roles using their kill button on Infectious, they become infected.
- Infectious also gain a decreased kill cooldown for every infected players or increased kill cooldown for every kill depending on the setting. Depending on the setting, Infected players will die if the Infectious is dead.