One way to vary a tangle is to change straight lines for curvy ones, or vice versa. In this case it's vice versa  I've changed all the curvy lines in Cadent to straight ones. (I'd like to write it 'Cadent with a small superscript 2 beside the t' but I can't seem to do that in Blogger so I'll settle for Cadent2.

Tangles: Black Pearlz, Cadent2, Crescent Moon, Stoic, Tipple 
Start by drawing the grid of circles, but draw squares instead and fill them black.
As with the classic, curved Cadent, start at the bottom of one shape and move to the top of the next one. This time, however, draw a straight line halfway out, draw up the height of the square, and to the right again to connect with the next square. Do this for all the rows, then turn your paper 90 degrees and draw across in the other direction.
Now, instead of the 83 words above, here are three simple drawings:
As with the original Cadent, this tangleation has many possible variations by making small changes or additions. The squares could be left white. They could be done larger, or smaller. You could Aura inside the Xshapes. If the squares are large enough you could draw an interesting fragment in them.
At the bottom of the next tile is Cadent squared. On the right side is a gussied up original Cadent. At the top is Cadent2 with rounding. (For a lot of ideas for variations of the original Cadent check out the blog post
here.)

Tangles: Black Pearlz, Cadent, Cadent2, Crescent Moon 
This effect is achieved quite simply by rounding all the corners. See the example in red below. Do this throughout and you'll end up with the pattern in the rest of the example.
Here are some other variations:
It's quite possible someone has steppedout this tangleation before, and possibly given it its own name. If so, I'd be interested to know.

Tangles: Cadent2, Dewd, Knightsbridge, Shard, Snail 