Roasts' hosts, also known as EMCEES or MCS, are responsible for introducing the roastee and other participants, setting the tone of the event, and keeping the roast running smoothly. They are the ones who keep the audience engaged and entertained throughout the roast. They are also responsible for introducing the roastee and other participants, setting the tone of the event, and keeping the roast running smoothly. They must be able to think on their feet and come up with witty remarks and jokes to keep the audience laughing. Roasts' hosts must also be able to handle any hecklers or difficult audience members. They must be able to think quickly and come up with clever responses to keep the roast going.