Eucalyptus
Overlooking / forgetting the death morale - you are right, my bad. With that in mind, I'd still probably only include either tier 2 or 3 (full coverage).

Nullifier
I consider the yellow attacks on tier 3 much better then axtra ability squares on base Nullmage.

Quantum Shadow
Fusionate I didn't even find in google translator, I don't know that it is a word :) .
The increased value - e.g. tier 3, even if it didn't have the ability, all 8 move-attack squares are worth more than 5, and the ability should have cost too, it's good. That's why I think from tier 1 the cost might be higher, tier 0 basically only has the ability for 2, so tiers above could have [moveset cost + 2]. This can threaten specific targets (e.g. Greed, special ability units) from quite effective range, while still being good defender (tier 3).

I haven't noticed the comment before, the ordering isn't intuitive to me even by Age.