Cleon
Legend
Let me see what I think we have here:
1) DR X/epic and immunity to poison with X big (well, it says "immunity to normal weapons" but I think epic is more sensible than magic for the DR)
Yes, something like 25/epic. Probably should give it a bunch of other immunities (criticals, stun, paralysis, et cetera) just so it isn't a pushover.

2) plane shift, as standard or immediate?
With its casting ability can't it simply use a quickened plane shift or quickened greater teleport if it wants to get somewhere else in a hurry?
Although I'd rather give it those as at-will Spell-Like Abilities, together with the "usual suspects" like true seeing.
3) reflect an attack as an immediate action. Does it take damage from the original attack? It looks like it from the original.
It does seem to take the damage, in which case we should try to find a different name than "reflect", since D&D spell reflection doesn't harm the target. Duplicate Attack? Rebound Attack?