These skills definitely eat up a lot of SP, so massive grinding will be needed to make really strong units.
Yeah, I realized that when I started thinking about what I wanted to put on Lyn...and then noticed that she only had 396 SP. Skill inheritance seems to primarily benefit 4* and under characters, since grinding them up to level 40 before promotion gives lots of extra SP as a reward. For example, my 4* Sharena has 1039 SP from all the level-ups I did to get her to 4*. Throwing skills on 5*-only characters won't be easy at all, because their SP gain dries up the minute they hit Lv. 40.
It's a very interesting addition from a mechanical standpoint. It seems to lessen the blow from not pulling 5* characters, and it also rewards you for grinding and sticking it out with low/mid-tier, low-star characters. For those whose favorites aren't so good or have crappy luck with pulls, it's a godsend. It also justifies the free characters (which they really need to update) coming in at 2* and 1*.
On the other hand, 5* characters aren't quite as valuable now beyond their stats and exclusive weapons, because they'll have a
much harder time paying for extra skills. Making a totally broken Hector, Lyn, or Takumi is doable, but will take
a lot of grinding. A whale has to work just as hard to create broken characters as a F2P player, and that's not even getting into how much time/money it'd take to get enough 5* characters to pass "+" weapons onto other units. I wouldn't be surprised if, from now on, top-tier units will always be 5* only.
