I used blue circles on any pools where you can make a good argument for multiple orbs. Note that this image assumes you aren't no-gacha or lacking in units.

The reason why the Resist Waves orb on Weaken #2 doesn't have one is because it's better to use dedicated anti-Wave units on a stage than using an entire orb slot to give yourself one extra wave counter. Same goes for any other resist orb. With that being said, the best units to give full Wave Immunity to would be Jiangshi, Cameraman, or maybe Balrog.

I chose the four 'best' units for orbs on the assumption that you can:

1. Put an orb on any unit in the game, and  
2. Max and talent any of them.

I'm also comparing end results here, not just the value of the orb. So, although Paris would get way more value than Jizo from a Cost Down orb, she's still worse than him overall, which is why she wasn't selected.

Although Cost Down only gives up to a 30% discount as opposed to Cash Back's 50% return, it's still the better option on spammable DPS units to keep them alive and to actually stack them. If a spammable DPS has Cash Back selected, you just won't get any money back unless they all die.

Cash Back is thus best used on an expensive meatshield, which is why Riceball is its best use. As for Dodge (All), Jiangshi was chosen because of his guaranteed Survive, meaning you'll always get at least two chances for the 10% proc. Berserker is best on Bahamut because of its applicability in Dojos and his insane DPS in general.

Thoughts on these choices? Did you all pick different orbs, or do you think an orb would be used better on another unit? I do think in reality, people's choices are influenced quite a bit by the units they actually use (and/or have), which is something to consider. However, I tried to prioritize objective strength above all else.

[Discussion] The best Ability Orbs from each Arena of Destiny (generally), and the best units to use them on.