Keep him, when you have better gear, you can make him work. My first leggo was Warchief....yeah, bad pulls happen.
Best advice I can give you shards-wise: start your mercy counter, save your pulls for 2x or Guaranteed Legendary event, and save your mercy pulls for Bonus Legendary (pull one get one free) event. Took me a lot of disappointment to learn that...it's the way to go.
As you go into the mid-game, please remember: gear is king, and you can't buy gear. Gear is the single aspect of this game that has no guarantees, no promises...all RNG, all grind. And it is so important, you can't spend your way into it. I know it may feel that the godly champ will make this game your b****......without gear, you're helpless. I am telling you this as an owner of Kymar, 2nd Rotos, and Elva Autumnborn I cannot afford to gear. My champs are ahead of my gear and it will take months before my gear is sufficient. DO NOT TRY TO BUY YOUR WAY INTO THE END GAME.
It takes time and patience....however you cut it, whatever you spend. You might as well just enjoy the ride, you'll be at it for a while. Good thing is....there are people who will help you here.
When you are at day 70 only, you are probably not in Doom Tower hard or late stages of faction wars yet.
You don't need Bystophus for your actual content of the game, but once you meet enemy waves with 3 high level Valkyries, you will be so happy for a 2 turn block active skills. His A3 skill is godlike. I don't have Bystophus, I use 2 legendary champs (Ruel + Cleopterix) to get the same effect of 2 turns block active skills in DT hard.
You got one of the best control champs in the game and really complain about that?
Just to echo another poster, if you do want to spend cash, i wouldnt get shards. If i was going to spend money i would buy gem packs and warriors circle packs and maybe energy and the forge thing (forgotten name).
He isnt the worst lego by the way, i would keep for faction wars, as mentioned the valks can be a pain when first completing FW.