First of all, for those who say that Architect is a darkspawn: I wish to ask a simple question, what is a darkspawn? Answer is as simple as the question; a tainted Human/Elf/Dwarf/Qunari. What are the beings that are called "the original darkspawns"? The Magisters who went to the Black City. Another Fact, regular "darkspawns" as we know (Hurlocks/Genlocks/Ogres etc) are mindless and soulles beings. A darkspawn cannot develop a mind/counsciousness/awareness on its own. Darkspawns Anders burn in the beginning of DAO Awakening were Templars a while ago. In the same sense, Corypheus and Architect are darkspawns that once were humans, Tevinter Magister to be more specific.
There are only two possiblities about the Architect: Architect is either an Ancient Tevinter Magister or the Ancient Tevinter Archon. If he is an Ancient Tevinter Magister, then he is High Priest of Urthemiel. If he is the Ancient Tevinter Archon, then he may Archon Thalsian. Who is Archon Thalsian? Archon Thalsian is the "First Priest of Dumat" (as Archons usually were) and the first person to wield blood magic. He learnt the art after personally communicating with Dumat.
Things we know about the Architect; he lies a lot and deceives others to make them work for him. Some Grey Wardens like Utha, for example. He even deceives Maric, Duncan, Fiona and Remille. He says that he wants to free the darkspawn and he uses only the dead Wardens' blood for that but Warden-Commander encounters a barely alive Grey Warden in the Architect's lair that was captured by the Architect's darkspawns. So we know that his intention is not about protecting or freeing darkspawn. If Warden spares the Architect, the Mother tells Warden that the Architect was the one who started the Fifth Blight in a failed attempt at making Old God Urthemiel his disciple. And if you think he is just a darkspawn emissary just because he said so, you have no idea about the things he told to Maric and Duncan. He is just too smart to reveal his true identity to a "Grey Warden Commander". "Hey, Warden! You seem like a tough guy, so let me tell you that I'm actually one of the Ancient Tevinter Magisters so basically I'm one of the reasons your life is f***ed. Actually I alone am the reason your life is f***ed since I raised Old God Urthemiel as the Archdemon. So, let us be friends and kill this broodmother for me will ya?" A Grey Warden's reaction to that would definitely be so friendly, so positive I'm sure.
We know other things about him as well; like he knew the location of Ancient Prison of Old Gods. He also knows a great deal about Blight and taint, Old Gods and blood magic. So well that he can invent his own version of Joining to create his own darkspawn army and even attempts to make a true Old God his disciple. It took more than a hundred years for Sentiels to invent Joining. He can cast very powerful spells (like raining fire upon his enemies. Andraste's battles against Tevinter was the last time such magic was seen/mentioned) and strangely he doesn't need red lyrium for that. Another strange thing is he seems to be able to tame/control dragons and even golems. Warden fights a dragon and a modified golem in Architect's Lair. It seems like he can send a person to the Fade even without needing something like Corypheus' Orb or Inquisitor's Anchor because one of the darkspawns sends Warden to the Fade using a strange device/tool in Awakening. Right before the part where Warden saves 'Justice' from the Fade. This reminds me of the saying "Throw me to the wolves and I will come back leading the pack". He was sent to the Fade and came back after saving Justice and commanded him around as if it was a new warden recruit. Badass.
In fact his personality is quite similar to Flemeth's personality. Deceiving others to make them work for them. Trying to avoid fighting the Warden and taking precautions about that so they don't die (Flemeth tricked Hawke into revive her with the amulet she gave to Hawke and Architect had Utha near him so he could possess her body if he was slain), know a lot about Blight, Old Gods and blood magic and saving/capturing important heroes like Maric and Warden. An odd coincidence.