More monsters mod

I believe the easiest way to implement a more monster mod for DS2 is to edit tuning_monsters.gas found in every region to increase the count number in each block, though I haven't tried such an approach.

However that by itself may get you more monsters to fight but unless you use a mod like the Monster Level Adjustment Mod, you will end up fighting nothing but green coded monsters due to the restrictive levelling system employed in DS2.

Normal play through DS2 and Broken World is very balanced so that as long as you fight normally, the monsters will be of similar level to your party. If you double the number of monsters you fight you will eventually distort the levelling system used by DS2 and so to balance it out the game will reduce the amount of experience you receive so that level progression will be within normal parameters.

So what is your aim for such a mod? Just for maximum carnage? A challenge? Higher levels? If you want the latter two, you'll need the Monster Level Adjustment Mod or alternatively edit all the monster templates in the game to adjust their expected level based on the increased number of monsters generated by the mod.