I will determine who is more powerful with 5 categories:
Intelligence, Strength, Speed, Armor, Abilities
Intelligence:
Indominus is obviously smarter than Giga
Winner: Indominus Rex
Points: Giga:0 Indo:1
2. Strength
Giga could push a fully grown T.rex into a ditch but Indominus could also push a T.rex. Indominus also flipped over an Ankylosaurus, crush a Gyrosphere and ram a van.
Winner: Indominus
Points: Giga:0 Indo:2
3. Speed
Indominus is quick for its size and we haven't seen much of Giga but I assume Indominus is faster due to Raptor DNA.
Winner: Indominus
Points: Giga: 0 Indo: 3
4. Armor
Giga has spiked armor on its back, but Indominus could take a direct hit to the skull with an Ankylosaurs tail without much damage. Indominus also could keep fighting Rexy after several raptor attacks. The Indominus also crashed into glass, shot by a helicopter, bit by a T.rex, smashed into a building, almost crushed by a closing concrete gate, and more. But Giga might be as powerful because of its size, armor, and its DNA was used in the creation of the Indominus.
Winner: Tie
Points: Giga: 1 Indo: 4
Winner: Indominus
5. Abilities
Gigantosaurus's abilities are jaw strength, armor, size, and Brute Strength.
Indominus has Camouflage, Strength, Intelligence, and Size
Winner: Indominus
Points: Giga: 1 Indo: 5
Final Showdown
It seems that Indominus will win but the Final Showdown will really show the true winner.
The setting is a lush rainforest full of trees.
The Giga comes into the forest to face the Indominus. The Indominus sneaks on the Giga and strikes the Giga's back with its long claws. The Giga is fine because of its armor and it whips the Indominus in the face with its tail. The Indominus instantly recovers and bites down on the Indominus and throws it onto the ground. The Indominus gets back up and runs straight for a lake and turns direction at the last second. The Giga falls in the water but drags the Indominus with it. They struggle as both of them cannot swim. The Giga wades through the water but the Indominus is having trouble because it can't fight well in water. The Giga rams the Indominus over and over. The Indominus plays dead and washes up on the shore. The Giga roars in victory looking at the sky exposing his belly and neck. The Indominus hits the Giga in the belly and rams it into the lake. The Indominus wins!
What Battle should I do next?