What should I do with SXander?

Level 1, +Attack -Resistence (optimal IVs)
What should I do with him. I dont like this character and its possible I dont use him so much... he is also not a great unit.

a) Keep him, and build him.
b) Fodder: Fire Boost 3 or Infantry pulse

What units are good with Fire Boost (I know Arden can work with it)

What units are good with Infantry pulse? Does Infantry Pulse from different units stack? So if I have my Summer Xander and Marisa in same team, do the allies get -2 to their special counts? Thats pretty op and could work on my Fjorn for example. Or on my Lonqu.