Galactus Vs Ultimate Thanos w/CC

After the events of (Ultimate Comics) Ultimates #30 Ultimate Kang time traveled further into the past to find the one person she believes can prevent the universe from dying - Thanos. She arrived on the planet Acheron and confronted Thanos (with Cosmic Cube): showing him all the things that will happen. She says the Cosmic Cube is the only weapon strong enough to stop Galactus however, only Thanos can use it effectively. He heeds her warning and kills her. A few centuries later he decides to act and teleports through time to the exact location of Galactus. Who wins?

Galactus is above cosmic cubes... IIRC Kubik himself admitted celestials are more powerful than him and Galactus has one shouted them. Mismatch

So i assume we are talking about cosmic cube without the self imposed limitation, what happened to Thanos last time might come into play, his subconscious desire to kill himself, well killed himself :p

With the cube thanos might be a match for him surely. I don't know if he'd win but it would be close