That L2 Warlock, on nominal difficulty, should have roundabout 10 Attack and 15 Health. Now, we see that a lot of exploration was wasted, however an L1 Halfling character, even with all boosters picked up, would have no more than 6 Attack and 13 Health without gods/spells/items.
So, if there is no class feature impacting the Chemist's abilities, it would have taken her 3 attacks (with possibility of 1 tile regen), to deal enough damage to fell the warlock. That would imply taking 30 damage, which is a bit too much, and even assuming an abundance of potions it would not seem smart (i.e. it would take 3+ health potions to kill that Warlock, highly unlikely that dislekcia would invest so much resource into the first kill, except maybe to play mind games with us!

).
So, the answer most likely lies in the abilities of the class. The class may have, oh, 25% Magic Resistance, or so, to reduce damage taken. The class may have some means to do additional damage - maybe it has a starting glyph (PISORF? BYSSEPS? some shiny new glyph?), which might help fighting the Warlock. Maybe it has some cool potion-related ability. Maybe it has bonus damage, Damage Reduction, or some other relevant ability. Like, getting some benefit (temporary attack bonus? CP?) from exploration at maximum health+mana; being able to mix potions to combine and/or boost their effectiveness? or having outright a potion effectiveness boost (which would reduce number of potions needed to kill the Warlock).
"Thinker", just without the "ache".