If it's the level 30 (rare slab) - You don't really need anything other than a good assault rifle (or epic/legend weapon of choice) and a pal helping, build the summoning altar in a boxed-off corner of your base to avoid needing to destroy your base and dump about 10 assault rifle magazines into the boss. It should be dead. If you're below level 40 you might need extra pals helping.

If it's the level 50 (epic slab) - Have an organized or empty base to box in the boss and keep all of your pals near it. You will want a minimal of 15 base pals that have attack boosting stats and souls dumped into attack stats. It's suggested to have all of them Dragon types. You will also want a player damage swap to Dragon style for boosted damage, for example most people ride Chillet while shooting a rocket launcher or AR. If you're not the best player try using a recovery med to heal health during the fight, and have a decent amount of your pals boosted in attack to do more damage. Be prepared for the boss to heal itself near the end of the fight.

If it's the level -unknown- (legendary slab) - Have a very clear open area for a base, with nearly nothing in it. Ride Chillet / Spam legendary rocket launcher or assault rifle while riding Chillet / have 15 (or 20 if you do that) pals at your base with a minimal of 50% attack boosts and every pal soul attack section full on each pal, they should all be dragon damaging types for the first 15 (or 20) in your base. Be sure your 5 pals with you all have Vanguard, and use a gobfin or multiple gobfins for further player damage while they're in your party. From there, about half way through the fight you will have almost every pal unconscious and require you to swap them out by quickly spamming them all back into the box, while bringing out another 15 (or 20) of your best pals. You'll want recovery meds and will be taking damage throughout the fight. Be expecting the boss to heal a substantial amount towards the end of the battle.

Congratulations you should have a basic understanding of the new boss by now. The rewards are not very good for the -unknown- level one compared to how difficult it is, but thankfully it's not an Achievement. If you're going for the 2 new Achievements you only need one kill of the standard version and one kill of the level 50 version. Good luck.