The 20-year-old defenders formed a daunting partnership in the Arsenal Under-16's backline during the 2007/2008 season, and are hoping their stay with the Eagles will be a repeat.
Depsite making their debut appearance in a 2-0 pre-season loss to Singapore Armed Forces, the duo are still eager to see what the S-League has to offer.
"It's a great opportunity to improve," Nicholas told The New Paper.
"It's not easy to make the move (here) but, if you want to climb the football ladder, you have to make hard choices and I didn't have much hesitation deciding to come to Singapore."
"Football is football worldwide, whether in Asia, South America or anywhere else," mentioned Obed.
"It doesn't bother me where I play as long as it helps me achieve my dream of having a long and successful football career."
Newly hired Geylang United coach Mike Wong has been impressed by the pair so far, praising them for their numerous qualities.
"Rhema is a competitive player and I see that extra something I'd like the team to have, while Oliver is very tall and very vocal," said the 46-year-old.
"Their having played together is an additional advantage, but I think as individual players they've also got good ability."
The Eagles have also added 25-year-old Slovak midfielder Jozef Kalpan from Tatran Liptovsky Mikulas to their roster.