A guide for the 10 companions achievement, or just a fun class guide if you want to have your screen clogged by shadow clones.
If you want to be boring, another easy way to get the achievement would be to get voodoo doll, a friendship charm (to get 8 voodoo fiends), and the Ancestral Aid trait for the two spirit companions for a total of 10 companions.
Agility. If you get any movement bonuses, it increases attack speed. Increased attack speed= more swagger proc, which means more shadow clones.
Alacrity. Gives more attack speed based on dex scaling of weapon, up to 35% with S+ scaling.
Intuition. Doubles dex point worth, which will double whatever attack speed you have from that. Pairs well with agility.
For weapons, the higher the attacks per second the better. Anything 4 or over should work. A few examples would be the Dartling Gun, Gatling Gun, Maxibee, Rapidfire bow, etc.
I used Grandmaster Shurikens when I did it.
Voodoo Doll. First off, companion weight for these guys is .25, so without any companion size upgrades you can have 4, which is already about half the requirement. Second, each voodoo fiend gives you a 5% increase in attack speed, so it is great to have.
Tiefling Gloves. Gain attack speed based on crit chance. If you have a decent amount of crit chance on your run, then these would be great.
Sin Treads. Gives 10% movement speed per curse, which can be really nice if you’re cursed af and have the Agility Trait.
Peg-Leg. Each gold you have translates to 1% additional movement speed, capped at 100%. Good for same reason as Sin Treads.
There are many, many more combinations you can do for more attack speed, but for the sake of some simplicity I’m not going through everything.