The item this Slaking held was a Focus Lens, which ensured its accuracy. Accuracy was crucial for Slaking.
Because Slaking needed to rest after every move it used, missing an attack would leave it helplessly taking hits for a long time.
Only by ensuring that Slaking's moves landed could its exceptionally high base stats make up for its Ability's shortcomings.
Du Ling had clearly put a great deal of thought into Slaking, teaching it moves of many different types.
Slaking was a pure Normal-type, so its own type offered no advantage against any other Pokémon type. Teaching it a variety of other moves was the right choice.
From Slaking's basic capabilities alone, Zhang Cheng could tell that Du Ling knew how to train it well.
"Slaking, use Amnesia!"
After sending Slaking out, Du Ling spent its first move boosting its Special Defense. Amnesia could sharply raise a Pokémon's Special Defense.
Slaking had high HP, Physical Attack, Special Attack, and Physical Defense. Its only relatively weak point was its Special Defense.
Du Ling naturally understood this well, so his first priority once the battle began was to boost Slaking's Special Defense.
With Slaking's tremendous HP, taking a hit first would hardly matter. As long as it could raise its Special Defense, the trade was worthwhile.
Upon receiving Du Ling's command, Slaking nodded lazily and converted Psychic-type energy into a special form of energy.
With that energy enhancing it, Slaking's Special Defense rose sharply.
"Kingdra, use Water Spout again!"
Seeing Du Ling order Slaking to boost its Special Defense with Amnesia, Zhang Cheng instructed Kingdra to attack with a special move.
Even after one use of Amnesia, Slaking's Special Defense would not exceed its Physical Defense, so a special move remained the best choice.
"Hah-tss~ Hah-tss~"
Kingdra unleashed the Water Energy within