What Are You Gonna Do With Jamke?

Nothing.

I have Bow users that completely outclass him in every way. He's going to remain as a bench warmer for now, but in the future he'll be fodder when I get units that can effectively use Heavy Blade. (I have none so far.)

Probalby keep him benched.
I have a love for GHB characters in general, but Jamke.
He's not aweful, not even bad but he falls in the pitfal of being too similair to an existing character.

Lyon and Walhart get away with this (being close to Sofia and Fredrick) by being a cheaper to build version.
Jamke is the same investment as Leon, but minus the IV and merges.

Besides, Jugdral has a lot of great characters, but Jamke isn't one of them.

Nothing for now i just don't know what to do with him, i have some archers at 5* that are better. I would consider him if he had something usefull, but HB and CA is weak for his statline, or if he was horse archer that would at least gave him a niche.

I already have a 4*+10 Leon who is better than him in every stat, so i guess i'll just farm HM on him

Build him, maybe eventually merge him but probably not merging for a while. I got others I could merge first like Catria, L'Arachel, and Ares. Plus I do also want to build Julius at somepoint, but haven't bothered with him as of yet.

I'm going to eventually use him as a hero merit battery to promote and make more 5+!0 severas or cordelias because there is nothing in the 2-3 star pool that is worth making 5+10 anymore.

Nothing; his stats are garbage to me

I will make one of the 4* to level 40 and send to the bench, and then I will make notebooks of the others.