Megistotherium

Both creatures are level 26 with no boosts, enhancements or Omega training. Every unlocked move is available, including low-health variants, with delays, cooldowns, priority and speed order. The simulation applies armor, shields, dodge, cloak, critical hits, critical chance buffs and reductions, damage buffs and reductions, vulnerability, rend, healing, devour, damage over time, stun, daze, resistances and their reductions, cleansing, removals, immunity and counter-attacks. Daze stops the dazed creature's counter-attacks.

Stun, dodge and daze chances are counted as weighted outcomes, not sampled, and speed ties are split evenly. Critical hits count at their average: every hit adds its critical chance times the extra critical damage, so the damage shown in a battle includes that average. Each turn shown follows the most likely roll. Each battle is a fight to the knockout between these two creatures, so moves that swap the user out (Retreat, Rampage and Run and the like) are not used while another move is ready, and a win that can come sooner is taken sooner. Swapping, swap-in and escape abilities, taunt and flock damage limits are not modeled.

Every non-Omega creature is first screened against Megistotherium in a quick estimate: up to six turns with a smaller search. The strongest candidates are then played out in full, up to eight turns, and any creature in the full list plays its full battle when you open it. A full battle can disagree with its quick estimate; the full battle is the better guide.

Battles are simulated at levels 26 and 35. When the build above is set to another level, the nearest one is shown and labelled.

These are simulated results, not guaranteed wins. A critical hit that lands, or one that does not, can change a close fight.