Lupine Warriors get an attack boost after they defeat an enemy at the expense of a proportion of their own HP, so they’re best used when defending against small enemies like Tubbies, Marines, Ballisters, or Penguin Warriors in order to get a huge attack-power boost.
The HP lost from Bloodlust will also quickly Enrage Lupine Warrior. That said, Lupine Warriors don’t have a ton of HP to begin with, so you’ll definitely want to pair them with a Miracle to keep them alive!
Lupine Warriors strengths are also its weakpoints. Since it needs to lose HP to get Enraged, and will continue to lose HP because of its bloodlust ability, it’s best to try and sap of it all its HP as quickly as possible. Surrounding it with Terminites, for example, will force it to lose HP from its bloodlust with every tiny Terminite it kills, while also getting chomped on from the other surrounding Terminites.
It’s also a good strategy to just snipe them out with range units, killing them before they’re able to get to you. You can also wipe them out quickly with removal, such as Landmines or Warpigs.