It's easy to see comparisons between Hollow Knight and Ori and the Will of the Wisps, especially looking at the original game in the Ori series. However, where the two contrast shows how upcoming Hollow Knight: Silksong could grow by looking at the way its comparative series updated itself in its own sequel.
In some cases, the features that Hollow Knight: Silksong should borrow are either updates to existing mechanics from the original, such as fast travel, or some of the new ideas that both Ori titles pioneered. It could help raise the stakes of certain moments, and more permanently alter the new world that Hornet will travel through like what happened with the Infected Crossroads in Hollow Knight.
Improved Access to Fast Travel
The most important aspect of a metroidvania like Hollow Knight is the map itself, complete with interconnected areas that slowly unlock as players earn abilities to assist in traversal. As a result, a major part of the original Hollow Knight includes walking through the various locales repeatedly. There are some fast travel mechanics in the original, such as the Stagway, but the locations and costs for these can still make hunting down specific charms and secrets a hassle.
A simple solution to this issue the Ori series used is allowing the player to instantly warp between the Spirit Wells directly from the map. There is a way to make this work similarly in Hollow Knight by only resting at benches near the Stagway, but that can make the path to bosses and other challenges brutally long for the sake of active fast travel. Giving players a more immediate way back to the fast travel locations through Hollow Knight: Silksong's biomes could go a long way to easing struggles in the endgame.
Ori's Chases Through Hazardous Environments
In many cases, neither Ori title excels when it comes to the boss fights, instead letting the platforming stand as the star of the show, including during the final encounter. Considering platforming is one of the high points for Hollow Knight as well, with one of its most notorious DLC additions being the Path of Pain, this might be somewhere for Team Cherry to take inspiration. One of the most impressive showings even with limited abilities in the Ori series is the escape from the Ginso Tree.
This type of high-stakes situation with a ticking clock threatening to kill the player if they wait too long to make decisions could enhance some of the Team Cherry's platforming. Specifically, if Hollow Knight: Silksong's new areas include a high-level platforming section like the White Palace and Path of Pain, this chase and escape mechanic could enhance these difficult moments. While these sections often acted as boss encounters in Ori and the Blind Forest, they could also be strong additions to the Hollow Knight series.
An Evolution of the Bash Ability
When it comes to comparing and contrasting Hollow Knight with either Ori title, it's impossible not to mention the Bash ability that sets Moon Studios' development apart. It's a unique ability in Ori that allows for extended traversal, as well as redirecting enemy attacks back toward them or in other directions to open secrets. Some fans of other metroidvania titles like the retro-styled Shovel Knight might recognize the same idea in the Specter of Torment campaign as a key to traversal.
The key wouldn't be to simply drag and drop Bash into Hollow Knight: Silksong, but to give Hornet an evolution of the ability involving her needle and string. Since Hornet's weapon sets her apart from the Knight in the original and all other fighters seen to use a nail, giving it special abilities would work with what has been shown of Hollow Knight: Silksong so far. What might work best could be to rework the Bash into a type of grab that could only work with the string Hornet uses.
This could be accomplished by Hornet temporarily containing her target in a cocoon of string. The utility wouldn't be quite the same as redirecting attacks, but could give an extra boost to height while also giving players a needed moment's reprieve from the onslaught of enemies. Overall, the key to taking this lesson from another title into Hollow Knight: Silksong is more about evolution than it is about directly pulling features and mechanics from a quality competitor like Ori.
Hollow Knight: Silksong is currently in development.