I think aizen bankai will likely be in his reitsu . let me explain his reitsu will take aizen form him self which means a copy of aizen but more nerfed in term of intellegence and of course make enemies felt like it's the same power as original
I wish we could see more of ichigo's vasto lorde form but in a way like, someone close to him gets really hurt or dies, and then he turns into vasto lorde and absolutely humbles the enemy with his pure rage and brutality, vasto lorde has so much potential to be this one scary wild transformation that makes even the most calm and steady person, a brutal angry wild monster needing to see blood and kill others. I wish we could see vasto lorde as this