Complex sentence: The next year, as a marketing stunt, HubSpot claimed it received a cease and desist letter from "Kronos Media" about its Inbound University and created a character "Captain Inbound" to defend HubSpot from an "evil" interruption marketing firm.
Split into simpler sentences: The next year, as a marketing stunt, HubSpot claimed it received a cease and desist letter from "Kronos Media". It created a "Captain Inbound" character to defend HubSpot from an "evil" interruption marketing firm.