I came THIS close to being 1 shot by thise double giants (they were way more dangerous than the single titan after).
After that i had to make sure my friend leader thing was someone who would jack up my hp every time i was reaching a final/second final boss.
But then i made an ogre/lit sombie team, and got myself some dublits, and a dub mythit. They made things so much easier for me, and i STILL use 2 dub mythits in my group. They are from the expert friday dungeon. Its fairly challenging your firat times around but doesnt require gear/monsters at all beyond an ogre and some lits (sapphit, rubylit, etc, thise little ghosts lugging an orb).
Just so you know an ogre leader makes it so as long as your hp is >70%, you'll survive a hit that would 1shot you with 1 hp. It has no cooldown but your hp must reach 70% again. Thats why lits are good because their recovery stat is way higher than their hp (everything remotely difficult in friday dungeon will likely 1shit you anyway so why not). Just make your friend leader in that dungeon a shiva, lilith, neptune, or something that bypasses defenses somehow (partial defense reduction wont help). Use them as an ohshit button (multiple dudes attach on the same turn and you know you cant kill all but 1 in time).