Phasing isn't listed, an insult to the one X-men character named after a real person.

I'd also consider Sage's computer-like mental abilities.
BTW I couldn't help be reminded of this;
"Wow, that's a great question.
A tough one, though.
What does one gauge
his response on?
Physical prowess?
Keen detection skills?
The ability to banter well
with super villains?"
-MJ