Sig decided it was time to put agressiveness aside, for now, and answered.
"Nice welcome you're giving me... I just thought you guys were one of those patrols or raider groups, which are practically the same thing."

Sig knew he had to get to know these people to effectively fight together with them. He was mostly curious about their abilities and powers. This waterman seemed fierce enough to be promising.
Sig stepped forward. "I'm Sig, and this is Spike." He said nodding towards the giant turtle. 
He listened to what Will said. Vygorns must be what they call those shady dudes that are always everywhere, telling people what to do and killing who doesn't obey the rules. Sig dealt with a couple already.
He looked inside the cave for a second then decided to point out the obvious. "If you guys have nature powers, why dont you just rebuild the place?" Maybe these guys were actually idiots with supernatural abilities.

The last thing the man said though, was not something he was really happy about.
"Protecting humanity? Why would you ever wanna do that? They'll want to kill you on sight. Everyone will want to kill you. I learned... but my friend didnt." He lowered his voice "He's dead and I'm not"
He was quiet for a while and decided to join his kind... they will realise, with time.

"All right" he sighed "you can count on me".