I am running an offensive team of +def -spd Effie, neural Ninian, -atk +res Lyn and Bonus on my alt. Overall it works pretty well, but I have to keep Lyn in the back if they are running Hector and if they also run a green mage, Lyn will then be too hurt to solo him, breaking my deathless run.

I've got non-SI +atk -def Bunilla (not willing to sacrifice my only Nino as she's +spd), +spd -res Minerva & +def -res Jaffar in reserve depending on the Bonus.

This is my alt account, so feathers are limited, but I can 5* 1 unit, candidates are:

+spd -res Kagero (Doesn't help Hector troubles)

+spd -hp Nino (A waste if I pull a second Nino to sacrifice to make Bunilla)

+hp -res ATiki (Solid Red, and takes care of Hector, but worse than the others)

+HP -def Chrom (Again Solid Red, but worse than the others)

Olivia (Replaces Ninian and should be able to handle Hector, but will only have 4* ruby sword)

Zephiel (Great unit and will be bonus, but 2 armors on a team...)

Anna (I already have Minerva)

Sharena (I already have Effie)