User blog comment:Ysana/A Tahnk Suhppohort concept/@comment-4199297-20120716094240

A champion with a huge hitbox (Cho, Hecarim's size + "ghost" ability) shielding/blocking for a champion with a very small hitbox kind of has a similar effect to the R ability.

See for ex. SivHD's "Reverse Support Hecarim" video http://www.youtube.com/watch?v=LFw-C__upQg

(though in that video it's primarily about shielding minions from the enemy carry to "deny" and only secondary about shielding/blocking for the carry)