This is a play that wants to be done wearing armour by who would like to make such a thrust. When someone attacks with a thrust or a cut, you make the cover, and then immediately counter as depicted.
The 11th scholar does not quite fit the pattern of the rest of this section. It is more general advice than a particular technique. Despite not being drawn as such, the play is specifically for when you, and presumably your opponent, are wearing armour.
Against a cut or thrust, make the cover of the master, sweeping your opponents sword to the side. Grab your sword in the middle of the blade, and thrust it into your opponent as you step through. This is the point shown.
A variation on exchanging the thrust, this play is the same as the 1st scholar of sword in armour. The only difference is that the master play of sword in armour begins in posta vera croce, and so is already holding their weapon in a half sword grip.
The core message of this play is not so much how to do the technique, but the idea that if you are fighting in armour, then stay close to your opponent, support your swords blade with your off hand and fight with thrusts.