Q1: How to control Armstrong?
A: Make sure you have Drgbase mod, as well as the other needed mods Aniszeus mentioned installed for it to work. Start game, find Armstrong in NPC spawn list, he's in the folder called Metal Gear Rising. Spawn him in, and hold click the button 'c', and place your mouse over him. Right click on him, find and click the option "possess". You now control him, anything more refer to the controls buttons in this mod description.

Q2: How to do heal animation (glow green)?
A: Aniszeus probably forgot to put the button to heal in description, but the button to do the Healing Animation where you glow green is the Walk Button. (default is ALT otherwise check the option.)

Q3: Anyway to change modify his health / damage / speed etc.?
A: It's in the tools menu on the rightside of the screen when you press 'q'. It's under the name "DrgBase", click it and it's in the tools section. Mess around the options if you want.

Q4: There is this >insert bug here<
A: Report any and all bugs within the comments of the Mod but do not spam them! Aniszeus is a hardworking modder, give him time!