Tresor, 27, is former ASEC Mimosas winger who was left without a club after recently parting ways with Egyptian Premier League side Harras Hodoud.
A club statement read: "We're delighted to welcome Mofosse Karidioula Trésor, a talented forward from Ivory Coast, to Marumo Gallants FC! A powerful and skilful attacker, ready to make an impact and strengthen our offensive force in Bloemfontein."
Treseor joins 29-year-old Togolese forward Adetu, who last turned out for Egyptian second-tier side Raya SC.
"We're excited to officially welcome Evanonye Kossi Adetu, a dynamic forward from Ghana, to Marumo Gallants FC! With his attacking flair and hunger for goals, he's ready to light up Bloemfontein and bring energy to our frontline," continued the statement.