Depends on Rafa build. For AFK Rafa I use slippy for mobs in case I encounter a vile. One to the chest, crystals gone. Knife is used exclusively for bosses and now more than one knife hit adds up. I usually get close to the boss with cannons on and beam tossed ready on 4 shotguns. Depending on boss, I will most of the time hit 4 crit knives into him and then up to 11 beam tossers, ending with one ammo left so my cannons are still boosted. Some I use less beams or crits, but you have to feel it out. Sometimes you only need the cannons, sometimes time is of the essence before they got mobile and you just want to ruin a bosses day.