is it possible to give sain/kent the knight crest in lyn normal mode

[Golden Karel]

1st play-through on my 3ds 

i have played the game before on my computer but i wonder if there is a glitch that lets you give sain/kent the knight crest on lyn normal mode  

[Robert Stewart]

According to the main site, yes.

https://serenesforest.net/blazing-sword/miscellaneous/hints-and-secrets/

"Whenever a unit is forced to make a movement, hold A, B, start, select, and any direction on the D pad to break free from having to follow the move. To avoid resetting the game, I recommend holding three of the buttons and a D pad direction before pressing the fourth.

A major use for this is to skip Wallace’s promotion in Lyn’s Story (Normal Mode). When you select Wallace, break free from the forced movement and make him (or another character) visit the nearby village. This will make his promotion event end without him promoting. A side effect is that you cannot press the B button before the promotion event ends."

[Zapp Branniglenn]

Once you've beaten FE7, you get the option to play Lyn Mode again on Hard Mode, which removes the tutorials. So you can choose not to promote Wallace and instead use it on a level 10 Sain or Kent. The Crest, along with any other items disappear from those units inventories at the end of Lyn Mode so there's no taking it with you to use on them later. I think just letting Wallace promote is the best idea. Keeping Wallace as a knight makes a later, potential chapter harder. And the only units I would promote as early as level 10 in the GBA games are healers and maybe the mages.