Summary
A deluge of Soulsborne games hit the gaming industry after the runaway success of Dark Souls, with many of those design trends now integrated into many games without much thought. This is especially true at the AAA level, and there have been so stellar games, though indie games have been influenced massively as well.
Without the budget of AAA games, many indie games have to find more thoughtful ways of incorporating Soulslike elements. You don’t need a stamina system to be a Soulslike, or overly-punishing combat. Sometimes it just needs strong level design, enticing enemies, and some strong direction.

Blasphemous, as the name likely already informs you, isa game deeply influenced by religion. It seeps into every part of the game, pulling especially from the historical religious presence in Spain. Blasphemous takes that to the extreme, with so much of the game’s atmosphere based around penance. You will bleed, it is divine.
Blasphemous uses the Metroidvania genre as its foundation, giving you the freedom to explore the world in a non-linear fashion. It’s combat is indeed difficult, but it’s more in the style of environmental storytelling and the more methodical approach to combat that it resembles the Soulslike genre.

Mortal Shell is as close to an homage of the Souls games as you can get without outright being them. Riffing off the original Dark Souls especially, combat in Mortal Shell is immensely slow. Every hit you take has to be planned for or will be severely punished. The areas and overall medieval stylings bring it somewhat closer to Dark Souls as well, though with less of the demons.
The real selling point of Mortal Shell is the eponymous shells. You inhabit the shells you come across, giving you access to new abilities and weapons, rather than crafting a build yourself. you may’t change these freely though, so be prepared to commit once you step into a new shell.

To many, Dark Souls' unique atmosphere is unique to the game itself, or taken from Demon’s Souls at most. Except FromSoftware has been making games like this for decades,most notably in the King’s Field series. And while From has yet to return to the series, something of a spiritual successor can be found in Lunacid.
If you wanted to know what the Dark Souls makes would feel like in a first-person perspective, Lunacid is one of the closest games to achieve that. The graphics are chunky, the world is non-linear, the moon cycles form a part of the gameplay. It’s an eccentric game by all means, but that’s one of the finer aspects of the Souls series, not just the combat.

Rats are fascinating animals because despite being saddled with a plague-ridden reputation, they are also the stars of plentiful media, Tails of Iron among them. In this game, you play as Redgi as you work to reclaim your kingdom from invaders. It’s a brutal world for one rat to fend off though, and that’s where much of the Soulslike aspects come in.
Despite being a side-scroller, the emphasis is fully on combat here. You have to worry about the weight of your armour, parry timing, how long it takes an attack to connect. There is build variety, there are brutal bosses, and there is plentiful weapon crafting. All wrapped up in a rat-shaped game.

A lot of Soulslike games tend to be dark and gritty, fantasy works that revel in misery. Not only is that a surface level interpretation of Dark Souls' own hopefulness, it also limits what the genre can do. These gameplay systems need not be strapped to hopeless fantasy worlds. They could instead be latched onto a crab that uses litter as a shield, for example.
Another Crab’s Treasure is as light-hearted as it comes, though with ameaningful commentary on environmentalism. However, combining the impermanence of your own equipment with Soulslike combat is quite fun, meaning no encounter is fully down to just skill but a degree of prep too.

Thymesia puts you in the role of a mysterious Plague Doctor-styled character known as Corvus. Self-explanatory name there. And while the game does indeed pull heavily from the Soulslike genre, it takes quite a bit of inspiration from another of FromSoftware’s titles - Sekiro.
Thymesia is not so grueling as any of these games, but still has a high skill ceiling. Parrying and deflection are essential components of the game, and the many spectral weapons you can summon offer great variety. It’s more about using all the tools at your disposal, rather than creating a single build.

When the Souls games started to take off, it was a while before many games actually had the chance to adapt their style. Salt and Sanctuary was one of the earliest to do so, and did so with flying colours. It was grim and brutal, but it also had a world that was rewarding to explore in its own right and a very distinctive art style.
Salt and Sanctuary focused on combat and exploration in equal measure, but also in granting you a frankly obscene amount of build variety. There’s a reason even now that it is seen as one of the best Soulslike games of its style. Even its sequel went in a different direction, owing to how specific the original was in what it achieved.