If your friends are Ranger and Archbishop, you should consider playing a tanky / melee character like sacrifice Royal Guard or Sura for end game PvM and MvP. Gene and RK would have work wonder as well for MvPing.
Rebel class is an independent class and has poor synergy in a party due to the fact the round trip pushes move outward from you, and it usually messes up RK DB or Ranger AS. I don't know who main a soul linker, it's really a slave class. You will not be able to go mid-TI and high TI with your friends due to level 99 cap.
Another thing to consider is that Rebel leveling is different than Ranger and Archbishop. Rebel level twice as fast than Ranger and Archbishop and it only limits to level 160. This is because Rebel doesn't need job experience. There's a bug that you gives you 50 job level before you hit 100. Ranger and Archbishop will level at biolab level 4 after 141, while you will be doing Nightmare Clock Tower to 160. Rebel is pretty much a dead weight in bio4 due to weakness against magic users like Celia Alde.