The pace is much much faster in DS3, partially because stamina recharges much more quickly and actions cost a lot less of it. DS3 is tuned to almost Bloodborne levels of speed and agility. Its just a different gameplay feel.

DS2 in total contrast is exceedingly deliberate and methodical. Running past enemies without knowing exactly where you want to go is extremely dangerous, much more so than in DS1 or DS3. There are also just flat out way more enemies in levels in DS2. The density is honestly a little ridiculous at times, and common enemies are unquestionably at their most dangerous strength and aggressiveness in DS2.

There are countless parts of the game where you need to meticulously plan out how to carefully take enemies one by one or kite groups into more advantageous positions to pick them off. It almost feels like a zombie game in that way. Mistakes are extraordinarily punishing in group encounters, and there are a LOT of group encounters.

Stagger is very punishing. Headshots are very very punishing, and almost every enemy type also has ranged magic, or a bow and arrow which is rage inducing at times. Also poison is extremely dangerous.

Besides that there are penalties to health for dying, and you need to use DS2's flavor of humanities to reverse it. or a ring/crown

Basically DS2 is extraordinarily punishing when traversing the regular levels.

however many of the DS2 bosses (there are a TON of bosses) are pushovers in comparison to DS3. Some of the DS2 bosses are total masterpieces, truly some S-Class level fights in there, especiallty in the DLC, but there are also a handful of truly trash bosses that are barely memorable. The levels themselves are a more challenging aspect than the bosses of DS2 in most areas Id say.