Legendary units are powered up versions of popular existing units that players can obtain for use strictly in PVP. This means that Legendary units can be included in your Base Defenders Platoon, in your Bunkers, and in Platoons made under the PVP tab.
These powerful additions can be earned by participating in PVP seasons to earn medals and Blood Thorium, which are spent in the Gear Store.
The Gear Store is updated periodically to include additional unlocks for capacity for these units, as well as upgrade tokens and tech that can be applied to them. Players can see announcements regarding these updates in our community Discord channel here: https://discord.gg/ANzJXmg