I can still make it to the Giant B10 boss, but he one-hits everyone on my team except Light Bearman, and he only survives with a sliver. Of course, this was with the attack buff on the boss, but I have no way to remove that in my current team.
So this got me thinking. You pretty much have to have healing to survive this, unless your team is just godlike. For me, healing is Light Bearman; I have no one even close to his capability for healing. I would love a leader that increases hps for my team, but the best one I have is Water Warbear, and that's only 15%. I have a couple other element specific hp leaders, but none that I really have great creatures in. And as I said, Light Bearman is pretty much a requirement for my team, so any hp leader needs to be either Light or generic. However, Light Bearman has a leader skill of +30% defense for Light. Not great, but best I've got.
Combine that with Light Vagabond (15% damage reduction to group) and Inugami (group heal along with remove buffs from target (fuck that attack buff)), and maybe it is survivable. Add a 4th Light damage dealer (for me that might be Amazon, since it has two skills that do damage based on mob hp, but not sure that is available in an SD, I think I got mine from a L/D scroll), perhaps a Light Succubus that most of us got from the event or even Bounty Hunter from the reward.
Unfortunately I can't even begin to test this theory for awhile until I level everything up, so I'm hesitant to even begin. Any monochrome team with a specific hp leader might be feasible (wind obviously being best if you are doing B10). I have a Dark yeti that gives +25% hp to Dark. Combine that with Salamander (deals extra damage proportionate to target's max hp), Dark Phantom Thief from event (guaranteed stun on trash every 3 turns if you max crit), and then whatever dps you have might work too. Unfortunately I have zero other hp leaders for specific colors, but I'm sure someone does. Just a matter of seeing if it works. Haven't looked at Reddit lately to see their ideas, but I have to assume hps and/or defense is the name of the game now, right?
EDIT: Jesus, how could I forget there are 5 slots??