I got some great help earlier so I hope I get the same help again <3 Here is my issue, I took Chrom to level 20 I think twice and on the third attempt as a Paladin, around level 9 he stopped getting stats. Not a single thing all the way to 20. However, there is a team I'm fighting that are all level 1 but with 80 hp (I have 80 as well) but they one shot him every time. This leads me to believe I can still increase his res/def but the only way I know of is those rare items that increase those stats.
However, if I choose a different class do you think his stats will go up in those categories? Like I am maxed out in Paladin but if I did Mage now he would increase in the mages stats? I am afraid to do this on my own as I don't want to lose all my str if I turn him into a mage or something else.