hey sazini,
i don’t know which characters would fit. since this is a “mini” set. the included ones will for sure. and probably those from my free game jam assets will do: https://s4m-ur4i.itch.io/free-sprites-elements-8x8-retro-pixelart-platformer-brawler
hope that helps for more advanced sets have a look at my metroidvania sets:
https://s4m-ur4i.itch.io/2d-metroidvania-soulslike-pixelart-tileset-with-characters
or this one
https://s4m-ur4i.itch.io/huge-pixelart-asset-pack
the advances ones will not fit the mini series. but there are 5 metroidvania sets available which share the same tile sizes. by adjusting colors all will be one gigantic set.
regards,
sam