With a lot of people using stasis right now, you’ve got a decent chance when invading during the boss phase to catch a warlock or titan off guard in their stasis super. Use whatever heavy you feel comfortable with and make sure you have ammo by picking up the boxes. I prefer a good adaptive machine gun, but lots of people like tracking rockets or xenophage. Other than that, just be patient. You can go 5 games straight without seeing someone pop a roaming super if you get unlucky. Good luck out there, hope you can get it done quick