The Heavy deconstructor, 4*, should have a 5* version of it. The damage is increased by tiny bit and when the bomb explodes, it causes a explosion. After the explosion, it makes extra bombs appear around like the crystal bomb series but instead of appearing in a circle, they appear like when the bomber gremlin throws the bunch of bombs, in a random scatter, but always scatters in a way that covers more than a semi circle. even though the bombs might not hit, the high damage and vs construct by high makes up for it. The number of bombs created after the explosion is six or eight. The damage should still be normal damage. The bombs that are created should take a little bit longer to explode than the crystals to allow the enemies who have been knocked away by the first explosion can have time to walk to them. Because the damage of the initial explosion is only increased by tiny bit from 4* to 5*, the bombs created makes up for the damage.
P.S. This is just an idea and if something seems not good then please suggest corrections.
You're proposing a normal-type shard bomb, with a large central blast, and high damage vs constructs. Sounds cool in theory, but in order to balance it, they'll probably nerf the central explosion so much that you HAVE to hit with all the little gremlin bombs to do any real damage. I suggest just leaving it as an ordinary blast bomb, it's easier for the developers to make and is more reliable in solo play. Try using regular shard bombs, so you can see how they work, and the flaws most people find in them.
The random scatter is cool, but bad. It makes the damage unreliable, since you have no clue where the bombs are going to land.