Taking the cranks off and rotating them 90 degrees will confirm whether the axle is twisted. If it is, it’s not necessarily a problem. The amount is barely enough to notice when riding, and should not keep you from doing any kinds of tricks.
But if you do a lot of hopping, that axle may be already on the way toward eventual failure. Usually there is little warning before they break. If you notice it’s twisted further someday, then it’s probably getting close to failure. Or it may just stay like that for many years. Really it’s a matter of how hard you ride on it.
Tons of hopping, even just low hopping in a gym, can eventually do this to a square taper axle. But if you have good hopping technique, you can do it virtually forever without axle problems. Taking the cranks off and looking for cracks around the base of the tapers will tell you if it’s starting to fail, but often there’s nothing to see until it happens.
Oops. That looks like you need a new wheel. Take the cranks off, clean all the surfaces and put them back on 90 degrees round. There is a tiny chance that they will be a bit better. (Maybe one is badly seated now or something.) When you take the cranks off, match them up side by side just in case it is a bent crank and the hub’s OK. bent cranks are cheap and easy to replace. A twisted hub means a new wheel or (for an expensive wheel) a new hub.
A ratchet w/ a 14mm socket. And you’ll probably need a crank puller as well.
Another option would be a cheap crank puller like the ones sold by pyramid which have a socket on one end and you can put a regular wrench on it to turn it. They’re not very expensive either.
A crank puller is an essential piece of kit for any unicyclist using square taper cranks. It helps you to swap cranks according to the planned ride, and you mood. They cost about as much as a pizza, and last much longer.