Shrinking Hulk doesn't work (already been tried and failed), messing with his molecules doesn't work. He'l has no way of winning this. World War Hulk is physically above him and WBH would literally wreck him.
H'el claims to be Kryptonian but has also shown various abilities that neither Superman or Supergirl possess. However this could be explained by the fact that H'el has been traveling the galaxy for so long and absorbed energy from different colored suns giving him a variety of abilities. As a Kryptonian, H'el's body acts like a "solar battery", absorbing energy to give him enhance abilities.
His abilities common in Kryptonians under yellow suns include:
Super-Strength - H'el has displayed strength enough to engage both Superboy and Superman in a physical fight.
Flight - Much like his fellow Kryptonians, H'el can fly easily without any visible effort
Invulnerability - He has shown little to no damage after attacks from other super-powered beings.
Super-Hearing - He is able to hear from great distances.
Super Speed - He has displayed speeds beyond Superman's, but it is unclear if it was purely speed or if it was due to his teleportation abilities.
Longevity - H'el has claimed to be mentored by Jor-El, yet appears to be merely a few years older than Superman, Jor-El's son.
Total Recall - He seems to be able to recall memories in almost perfect detail.
Intellect - His intellect is vast enough to allow him to be the top student of Jor-El, one of Krypton's best scientists.
Super Healing - This is not certain. In his first appearance, H'el had multiple scares all over his body. Now, however, he is largely scar free. On the other hand, this could be attributed to artists failing to remember to draw all of the scars
His abilities never displayed by Superman or Supergirl under the yellow sun in the New 52 include:
Teleportation - He has shown the ability to appear and disappear at will, originally thought to be just super-speed, H'el has teleported others great distances in the blink of an eye, for instance, moving from the surface of the sun back to Earth seemingly instantly. He is also capable of teleporting the entire Fortress of Solitude at will.
Telekinesis - He has shown the ability to move objects with his mind, create force fields, and has displayed fine control of his telekinesis allowing him to affect things on a molecular level (as when he began to deconstruct Superboy to see how he was made). His telekinesis seems to work like Superboy's, giving him an understanding of/mental connection to what he applies it to as if it were another sense.
Telepathy - H'el has displayed several abilities that fall under the scope of telepathy. He gave Supergirl the ability to speak English and gave her the illusion that he was Superman.
Matter Manipulation - H'el was able to shrink Supergirl down to send her to the bottled city of Kandor, but expressed that he was unable to do the same with his own body, so the extent of this ability is unknown
Astral Projection - H'el has shown the ability to project himself to others when he himself is not physically able to accompany them. Similar to the use of holograms. However, this could be another application of his telepathic abilities.
I don't see anything on that list that makes a difference, especially with all the people Savage Hulk has destroyed with that same ability. He'l has not done a thing showing he can win this.
The same people impressed with Superman's shockwaves are saying He'l wins here against a guy who's shockwaves destroyed thousands of 100 tonners and destroyed a planet...