The phrase "and even more complex" is correct and usable in written English.
It can be used when discussing something that is already complex and indicating that there is an additional layer of complexity involved.
Example: "The problem is not only difficult to solve, but it is also multifaceted and even more complex than we initially thought."
Alternatives: "and even more intricate" or "and even more complicated".
And even more complex questions lie beyond the essential design.
"Freedom of Colors," his commissioned suite, was about 20 minutes long, and even more complex.
Secondly the cap is misleading and even more complex than the current system.
Feedback loops such as these are complex in themselves and even more complex when considered as part of an integrated global climate system.
Thus, the problem of guaranteeing survivability and reliability of VI is important, and even more complex than in single layer networks.
However, based on past experience of similar (and even more complex) systems, SAC can still be applied under a wide range of operating conditions, perturbations and even control saturation.
The patterns and ideas he examines generated fervent debate in his lifetime, and seem even more complex and relevant in ours.
An even greater challenge is to translate the behavioral correlations found by statistics into insights and guidance for designing and managing even more complex data systems.
Furthermore, Maynard Smith's model considers only trait relationships with survival, neglecting equally important and potentially even more complex relationships with fecundity and reproductive performance.
As industry and regulators wrestle with the intricacies of microarray data formats and submission, even more complex challenges loom: the data produced by proteomics and metabolomics research.
This assumption is completely in contrast with that described above for ROS, and contributes to making the functional relationship between oxidative stress and autophagy even more complex.
