It still not proven that Michael and Lucifer combined are equal to The Presence. Although eleveninches stated the issue # but I still havent checked it out. Its also not proven that Lucifer(or Michael) will suceed The Presence since The Presence is already gone and he didnt appoint any successor.
And Cosmic Cube, Lucifer is not purely evil. Lucifer is just a being who just wanted to live his own life and decide his own fate. But because he lives in The Presence's turf(the DC Multiverse), he cant achieve what he wants. Thats why he wanted to leave creation and wanted to have a multiverse of his own in the first place. He just wanted to be free of The Presence, thats all. He never had the desire to hurt people. He never had the desire to convince people to the "dark side"(hmm... sounds familiar that one). He never really cared about them to be honest. In fact, he even complained why people always blame him, the devil, of all their wrong doings, when he didnt even do anything to them.
So yeah. He just wanted to be free, because as long as he stays in the DC Multiverse, The Presence will always be the one who controls his life. And the very thought of that makes him really sick to the core.
Anyway as for the subject. I forgot another weapon of Lucifer ---> His Mind. Lucifer doesnt need to corrupt Adam(he doesnt even do that kind of stuff). He could just trick Adam into giving up HOTU, or not killing him, or better yet join him in his crusade. He is the God of Deception after all. Now Im not saying that its 100% sure that it will happen, but its entirely possible. Unless Warlock cannot be tricked as well, which I doubt very much.