[nickjr]

Too thorough, I think lol

If I had to replace more than just Alrescha, then I'd replace Blue Odin. I don't think Aizen teams need enhances from an active skill unless you're trying to kill Kali or someone like that, so Blue Odin is just a great stat stick who brings 3 SBs and can kill stuff with blue TPAs--which you're probably not going to be focusing on (you'd probably only try to kill stuff with blue TPAs if you're short on dark orbs and have no actives that make dark orbs up--but what if Blue Odin was, instead, another monster who made dark orbs? you see lol)

If you don't need Blue Odin for his stats, then I'd put in one of the monsters I mentioned earlier that you could kick Alrescha for.

I would keep Blonia and Lumiel in there for their board changes. Lumiel in particular combos great with Aizen himself for bursting.

(Bicolor board alone
Pros: uses a single active, generates more dark orbs on average + orb troll is rarer
Cons: no way to fix orb troll (remember that this option is just using the single active), longer CD

4-color board + double orb changer combination
Pros: more consistent final numbers of each orb type (e.g. guaranteed 6 dark orbs unless you had locked orbs on the board), shorter CDs
Cons: uses two actives, more likely that you need to actually use both actives due to lower average generation of your desired orb color

The benefits and tradeoffs of using one of the above over the other are pretty clear, but people weigh the pros and cons differently depending on their personal preference, their playstyle, the other monsters on their teams, the team itself, etc.)