The Hive Lord is a monstrous beast of barbs, spikes, claws, teeth, and incredible strength. The primary strength of these creatures though comes through their psyker powers. The Hive Mind is in contact with the Hive Lord through a psychic link. The Hive Mind is the omniscient power that propels and guides the Tyranids and the Hive Lord serves as the commander on the battlefield, organizing the lesser creatures that make up the Tyranid swarm. The Hive Lord's synaptic power instructs and empowers weaker organisms, allowing them to act as a group and with surprising intelligence.
The Tyranid campaign is quite unique in that there is only one Tyranid Hero unit, as opposed to four for all other factions. The swarm that the Hive Lord leads in the Tyranid campaign is made up of everything from Rippers to Raveners. These units can be summoned to fight by the Hive Lord itself, adding ever increasing numbers and weight to Tyranid attacks. As the Hive Lord gains levels throughout the campaign, not only does this allow you to unlock new abilities for the hero but you can also unlock upgrades for the types of units that can be summoned. To start the campaign the Hive Lord can summon Rippers, small melee units that don’t deal very much damage. These can be upgraded to Hormagaunts and then to the truly lethal Genestealers.
The abilities for the Hive Lord itself often revolve around its synaptic connection to the units around it. Many of its abilities bolster these units in some way, granting them more health or healing, or in the case of Explosive Decomposition, using a death of a unit in the swarm as a weapon. With this ability a Tyranid killed within range of the Hive Lord's synapse will explode, damaging nearby enemy units. Regardless of abilities chosen, the Hive Lord, not counting abilities that boost health regeneration, is by far the most durable hero in the campaign, having more health at level 1 than many other heroes will at level 10.