Yeah it's Christian "Mabanga" Mwepu on the bass guitar. Bill Clinton even mentioned his name at 2:47 min "Ya Christian Mabanga mema nga na leka".
On Titanic it's Fiston Zamuangana Savimpi "Misapi ya Talo" on the rhythm. Patient Kusangila went at that time back to his bass-player rol sharing it with Alain Makaba.
I don't know for what reason, but I always preferred Intervention Rapide above Titanic, despite that mediocre quality. I think that it's because the power and that new style Japonais & Kakol brought in, while we were in the ndombolo-era. I remember people complaining about that saying that it was "manzanza", "makelele" and that it was music of the street. So they recorded Solola Bien on the vision of Titanic and went back to the ndombolo-style, having less noisy/aggressive sebene's, having Flamme Kapaya on the lead, who was at that time not really aggressive on his guitar until Burkina arrived. Inviting Djudju-chet, Maika Munan, Philiphe Guez and Guy Nsangue. But it didn't change their reputation and people still saying that it was "manzanza" (or maybe it was just hate) and they went then on the Kibuisa Mpimpa-album back to the original Maison-Mere style, which Japonais, Kakol & Christian Mwepu created in 1998.