Mechanized Armor

Mechanized Armor [Mount]

Your allies don't ride on your mount, they ride in it. Behind layers of armor.
Benefit: Your mount is heavily armored which prevents creatures from boarding and blocks line of effect between its passengers and all other creatures – including the rider. Once per [Round] at its rider's turn, if the rider is your ally, they may open or close firing ports (no action is required to do so). Opening firing ports re-enables boarding of the mount, and unblocks line of effect, allowing passengers to attack (and be attacked) while inside the mount. If the mount does not have a rider, the firing ports open automatically as a safety mechanism.