Bringing sub-weapons to the handheld games and nonlinear level progression, Christopher's return to Dracula's castle was an all-around improvement from the preceding handheld title.

Source: https://www.cbr.com/castlevania-chronological-order/

This game also marks a change in abilities through Richter Belmont, which opts for “item crashes,” which are special abilities from the character’s sub-weapons that release a powerful attack.

Source: https://gamerant.com/every-castlevania-game-richter-belmont/