The narrator's view of Ozymandias is at least twofold.
First, the narrator believed that Ozymandias was proud. When Ozymandias was in his prime, he thought that he was the greatest. He was boastful, filled with hubris, and probably thought that he would live on forever (at least his kingdom). The following words make this point clear:
'My name is Ozymandias, king of kings: Look on my works, ye Mighty, and despair!'
Second, the narrator believed that Ozymandias was blind to the fact that all things decline with time. Ozymandias should have known this from history. What kingdom has existed without decline? All empires, kings, and powers rise and fall. Inevitable entropy exists. That this is true in this poem is proved by the fact that nothing of Ozymandias exists. Here is how the poem ends:
Nothing beside remains. Round the decay Of that colossal wreck, boundless and bare The lone and level sands stretch far away."
The narrator might also have believed that Ozymandias was tragic.
In short, the main point of the poem is that Ozymandias' pretense blinded him and puffed him up.