Aside from Vernon's Eagle's Mark, he also had Silent Pursuit, which could help him track enemies without leaving traces or being detected, and Explosive Volley. It was a powerful ability that let him fire multiple explosive projectiles at once.
Even if he just carried multiple pebbles with him, they could become explosive pebbles in his hands! It was such an interesting ability if partnered with his Eagle's Mark.
Perhaps the only reason he was only an Epic Recruit was due to his weak physical defense. A single punch or tackle from even a mid-tier Zombie might kill him. So Shane had to give him light armor that provided him a high defense.
Needless to say, Shane gave him a Tier 5 Hunter Set, which was perfect for Vernon.
He had seen Vernon's skills already, and he knew that he would be invaluable, especially for their journey to Sector 20.
The other was Nia, who was actually from a mountain tribe before the Zombie took over their homes.