@XD0010Bigfan
If I may, I'd honestly choose to combine both.
But if I had to choose only one of them, that's a tough choice for me.
1. Because for one thing, it would depend on what kind of Mangekyou powers the MC may get, if he'll unlock that form of the Sharingan anyway. And if he might even get EMS eventually.
Other than the Susanoo being the third power (which I hope for because it's my favorite Uchiha Jutsu), what would be the other two?
2. But on the other hand, with Hashirama's arsenal, Sage Mode and Senjutsu is also one of my favorite powers in the Naruto series, plus Mokuton is also OP in its own right.
So, I'm honestly stuck on what to choose.
Unless, the MC might be able to learn Sage Mode even if he winds up with Uchiha powers? Maybe even combine it with his Jutsu, like his Susanoo?
I can't help it, I just really love Senjutsu.