Single player game question

I really like playing single player. I was wondering is there any character that can summon minions or throw down turrets?

Closest to that is Kleese, who can deploy turrets that recharge ally shields and damage nearby enemies (i think).

It would be kind of redundant because any character can summon minions or build turrets using shards, otherwise I think this type of character would already be in the game.

There are a few characters that have deployables such as Ambra’s sunspots or Marquis’ owls. You can review each and every character’s abilities here. But if you’re looking for an Axton-like character, I’m afraid there isn’t one at the moment. Partly because Battleborn is equal parts PvE and PvP, so having a turret or summon that can auto-aim and mow down hordes of bots and/or other players would be a bit of a balancing issue.

Can you explain how shards work? In regards to single player.

I think it works pretty much the same way, they still appear around the map in the same fashion. You still have your same gearbox, but there are also different things you can buy. I think you can buy minions to support you, not sure what else though or how many different minions there are.

are there any videos that show that?

Here is a video of a two-man team playing through the story campaign mode. You could also do this single-player.
Anyway, you can watch as shards are used to build buildables such as turrets and even a drone that follows you around.

2-man team in Campaign mode with buildables