The Final Battle Nexomon - Omnicron The Ziegler in The Chasm

This is the final battle in the nether world

NARA
We never got to fight Nara in the main story, which makes sense, but because of that it's cool that we still get to fight her here. Anyway, the usual high HP boss strat applies, but she does have a lot of HP, so it will take a little longer (especially if you didn't level up to get the ultimate moves for those that needed them). use Fire / Wind

THE ZIEGLER

This battle is almost like fighting Omnicron, except that this guy has a bit more HP. You can't take advantage of weaknesses, so all you can do is chip away at him with all your strongest attacks. And, just like fighting Omnicron, Normal types are useful here because they have no weakness, while Water has two resistances and one weakness. A slight difference is that Mineral actually is by far the best type to use in this fight, with two resistances and no weaknesses. This is because Ziegler uses Disruption Ray instead of Heavy Monsoon. Plant types get a reprieve, with only one weakness and one resistance. It still sucks to use Wind types (which is why I don't recommend them for these types of fights!).

Once again, you'll want to lower his attack and accuracy with moves like Snake Eyes and Dust Cloud. Then, switch to someone who can increase evasion e.g. Torrex, Hurristag, Kitsunox, Arctivore. Additionally, you can use Headbutt/Spinning Attack over and over to lock him into Confusion, and cast Block to reduce his damage to 1, which can be done by the same Nexomon discussed in the Omnicron final boss section earlier in the guide (Hurristag, Kitsunox, Luhava).

The main factors to watch out for in these Omnicron/Ziegler type fights is whether you have enough HP to avoid being one-shot, and whether you have the correct moves to mitigate/avoid the damage. Disruption Ray does around 300 damage (around 240 damage with debuff), which is why it's good to be a high enough level to have over 300 HP.