It depends, but Tough and Timid Lona both give numerous advantageous stats to Lona (mainly defense in the case of a timid Lona) so it helps her survival greatly.
Maxing either attack or magic attack (depent on personality) at 99 lv gonna make Lona a Rip n Tear monster (still die very fast if you're careless though)
Example:level 99 Lona got surrounded, Lona only receives 1 damage per attack but you can't retaliate at all, eventually Lona gonna get bruised which lower her def greatly, worse, if RNG screws you and Lona's clothes are stripped all the while, her defense gonna be null. All of these happen in less than 30 seconds.
So yeah, Offense is the best defense here, best to only 1vs1 in tight corridor and remember to bring and spam potions (unless if you're on hell and doom, then take care not to overdose)