itll only delay the next group if the boss is less than 60% hp when the next group tries to enter, and i believe it has a timer to finish him as well. Im sure the op is asking how many because they might live on a low population shard or they keep off hours and dont have access to as many players as the rest of us.
and if it was a richard waving contest then im sure the post would have went something like, "Me and my dual client disco character 'soloed' exodus in 10 minutes! beat that nubz."
but back to original ?
Exodus likes to move fast and leave plenty of area damaging vortices. a support character -heals/disco/Spellweave- that has great mana regeneration capabilities and LMC plus any other Buff items you can handle (fish pies, potions, balms, etc. both for healer and fighter)
the damage dealer of course should be maxed out on possible damage to non slayer monsters, so you might want chiv for enemy of one etc. or you can get a 100 DI suit and I believe i had best luck with a 100% fire damage weapon, maybe energy. HP and Stam regen is good for fighter to keep him swinging fast and alive. if theres room the fighter could benefit from alittle spellweaving as well, so he can cast attunement or aid in his own healing with gift of renewal.
most of all, with 2 people in there it shouldnt get too laggy so as long as you and your friend are quick at dodging the vortices, you might be able to take him down. hope that helps