Hydro-Man vs Aquaman vs Sand-man
Hydro-Man-Being able to transform into a watery substance, Hydro-man can access secure areas and small openings with relative ease and when his bodily mass is dispersed in this form it simply reforms, albeit slowly depending on how far apart the mass was. All of Hydro-Man's molecules remain fully under his control even when he is in his liquid state, as his consciousness apparently exists as a sort of vapor in this state. Hydro-Man can also merge with and manipulate larger bodies of water when he is in his water form. He can turn parts of his body to liquid while retaining the rest of his human form, allowing him to slip from a foe's grasp or have projectiles like bullets harmlessly pass through him. With concentration, Hydro-Man can also turn to ice and steam, but this exerts him greatly depending on the ambient temperature
Sandman-Can become a sentient mass of sand that can change shape and density to his advantage. Vast superhuman strength and endurance in his sand form