While group Delves got harder, an unannounced hotfix has applied a 20% nerf to enemy spell damage for solo Delvers.
Blizzard just released hotfix notes for today, but it's missing a rather large change that happened. All enemy spell damage has been reduced by 20%. For group Delvers, this 20% nerf is likely offset by other damage increases.
For solo Delvers, this 20% spell damage nerf will make a lot of the trash and mobs slightly (and I mean slightly) more bearable. This affects both single targets spells (i.e. Web Bolt) and AoE spells (i.e. Burn Away).
Health and damage mostly seemed to stay the same for solo players.
Will this change much? Probably not in my opinion. It'll make a few bosses that have massive magic damage abilities slightly easier, but part of the reason that Delves are so hard for solo DPS right now is because not only do the casts hit so hard, but the auto-attacks do a lot of damage but especially to clothies. I'm not sure why auto-attacks haven't been nerfed yet, especially considering they can crit!