you need to invest in Manashield 40, Barrier 40, Infusion 40, and LOTS of All Resist. eventually, that still isn’t enough. Dodge, Block, Sanctuary, and any other way to cause enemies to miss you. higher movement speed, lots of CC effects, kill them faster than they can kill you, things like that. on a side note, a Mod suggested in a post that Legend Reflect Damage works with Mana Shield, but I haven’t tested it yet, or seen any posts about that. Skill Points in Mana Shield does increase damage of Legend Reflect Damage.
I have used Wizard with +60% Dodge & +45% Block with Sanctuary, and using Ice or Prismatic/Ascendant with Elemental Crit to Freeze enemies, with Teleport to get out of danger in emergencies. my floor climbing wizard uses Fire & Ice with Crushing Flames & Frostbiting (on floor 1800+ m3). need to tweak it for more damage as I pass up floor 2k. uses a combination of Comet, Twister, & Skull Shield, with Stealth for emergency defense. ohh! I think I changed my Twister to Meteor recently, feels weird, as I didn’t like Meteor when I first started playing DQ years ago.
the Perma Stealth & 100% Block Builds are really only 99.9% defense. if your timing is wrong, or you are in the wrong place at the wrong time, you can still die. a Perma Stealth Build with Illusion Talents for enemies to miss you for Rogue, and 100% Block Build with Bleed Talent for enemies to miss you for Warriors (they so lucky) while Wizard just has Dodge, Block, and Sanctuary with Minions to distract enemies with.