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the Testing Dummy is random, so you never know how good or bad it’s defense really is versus your offense.
@anon18070926 is correct, many Players have learned how to get high Defense with high Damage Reduction and Resistance, and sometimes high Armor. @Mr_Scooty shared a Wizard Build that had 172.4k All Resist before it went into the Battle Arena.
this build was nerfed when the Mod’s changed MP Absorb to not work with Alchemy Resource (MP Absorb also doesn’t work with Blood Magic). but it still has a ton of All Resist.
what they do is take low damage at the cost of doing low damage to others. the way they win is that, every round that is a Draw, damage for both sides goes up 25%. so if you can survive by running around or with good defense, eventually you can kill them, or their low damage can eventually kill you faster than you can heal.
I’ve gone up against a few Tanks, and it takes a few Rounds to kill them, if they don’t kill me first.