If you guys are talking about raines use Snow (Sentinal), Lightning (Commando) and Vannile (Medic)
When he shields or heals go into the paradigm >>> (forgot name) (Snow (Ravanger), Lightning (Commando), Vanille (Ravanger)) and work on the chaining then when he goes back to offensive shift then go back to Solidarity (Above)... it will take a while but if you stagger him before lightning goes insane and beats him to a pulp then switch to (Snow (Commando), Lightning (Commando), Vanille (Ravanger) then you can juggle the guy till he's dead.
*quick tutorial on juggling* Wait till Lightning (or another Commando (Snow, Lighning or Fang only) to knock the enemy into the air and finish thier combo. Then unleash your combo and by the time you come down the other commando will be back up and using thier combo (This technique is best done with a Commando, Commando, Ravanger class.
By the time you read this though you will have had every character on the floor
...Your Welcome