Pantheon is classified as an assassin. I think there are two branching points, where he could be taken to be a fighter, or an assassin. I will list my rework ideas for both sides.
Aegis: Number of hits to proc upped to 5-6, but make it a full fledge BV effect.
Q: Procs on hit effects.
W: Ok with aegis change
E: Pantheon needs to gain some armor and MR while channeling.
R: With global change, radius reduced slightly, channel time decreased, damage reduced slightly but normalized, enemies caught in skyfall get knocked up.
Aegis: As above
Q: As above
W: As Above
E: Changed to a dash/damage skillshot.
R: With global change, radius greatly reduced, channel time decreased, enemy champions caught get rooted for a time.
If any questions as to why I did certain changes, comments, criticisms, and whatnot, feel free.