Oh, you have a really easy team for Beelz. Check it out.
Lead with Ceres for that 55% dark reduction. Then use a friend Awoken Hades (mine is +204 if you need) for the other 50% reduction for 22.5% of the damage taken only. This makes it all a timing game, less of a brute force.
Given your levels, I'd slap on lubu, baddie, vamp, drawn jester/chester. Check it.
Round one - they do 4576 damage each due to your leader skills. 9,000 per turn still sucks so kill them as quickly as possible.
Round two - This guy does 2,200 to 3,500 damage every two turns. Clear poisons, don't let them stack up and you'll be fine. If your brought Chester you can use him too but you kind of suck if you let that happen to you. Stall for all your skills, then set up the board nice and dark heavy before finishing him off. You want two 4-orb dark matches available for the next turn ideally.
Round 3 - It doesn't matter who you get, cuz Ceres is unbindable and her skill unbinds anyone else. Suckers. Both of these turn black at 50% so its important to one hit them at least 50%. If you get the Owl Fucker, you can easily get the damage with one TPA let alone two of them. Ceres enemy has high defense and you will end up 1 damaging her 39 HP down. Just heal after her 75% gravity before moving on. Again, set up your board for dual TPA activation for next turn if you get Ceres. It's easy enough and safe enough to do and the most important turn to do so.
Round 4 - You have three turns to kill this guy. I'd highl recommend setting up a board if you had Ceres then just baddie him. Makes this easier. If you have Drawn Jester, you can use a Drawn Jester + vamp combo here. Hopefully if you set up the board you can have an easy time getting him with no skills besides baddie, but use whatever you need.
Round 5 - Beelz. If you didn't use any of your skills cuz you set up a killer board in round 4, awesome. If not, then stall. He is dark when over 50%. (and beautifully weak hits under 50%) If you brought Chester, this is a good time to use him to stall. You let Beelz make poison orbs and dont clear them til its a bunch and use chester to clear them. Either way, I'd personally wittle him down to under 40%. This makes him do a 3 turn repetition where he does 50% gravity, then a 6431 atk turning poison to dark, then a 0 atk turning orbs to poison.
If you have chester, you take the 50% gravity then make sure to heal over 6431. Then next turn get hit and see those poisons turn to dark. Then the next turn watch a shit load turn to poison. After he turns those to poison, use chester's active to turn them to hearts, use vamp's active to turn those to darks. use hades' active for a gravity and a huge orb time increase. pop lubu for the nuke and then set up your TPA's. DEAD
If you brought drawn jester, you will want to wait til this same under 40% cycle, take the 50% gravity, then heal for the 6431 hit that turns poisons to darks. this time don't wait for the next turn and activate everything right then when the board is dark heavy already with no poisons to top you off after the lubu active. DEAD.
I honestly might even with subs lubu/chester/vamp/DJ and try to take out round 4 with no skills (or if I fail hit vamp+DJ last turn and stall on beelz)