This is what I imagine what the Epic Assasin should have looked like.
A massive warrior, holding a bastard sword glowing with arcane fire and a shield ensconced with runes. He's raising his sword for a killing blow, the light gleaming off of his shimmering reflective plate mail, the only visible chink a razor thin eyeslit.
The epic assassin is standing in front of him, wearing a cloak woven of shadow and a mask of darkness, casually shoving a red stilletto through that eyeslit. Poison drips from the blade.
This is what I imagine the Epic Loremaster should look like.
A Solar, armed with a weapon forged by the hands of the Eldest Good, girded in armor drawn from the heart of the sun, eyes blazing with knowledge incalculable.
He is borrowing a tome from the Loremaster, who sits, calm, fat, and unimaginably wise, in the midst of her Demiplane of Books.
This is what I imagine the Paragon Illithid should look like.
A warrior of the dwarves, proud and strong, a defender of his people against the horrors of the underdark, prepared to strike down any foe, no matter how potent - So strong is his defense. Epic Tordek, basically.
The Illithid, wearing substare plate armor, is calmly eating his brains as the dwarf lolls helpless against the cave wall. It's messy.