I've just got a catalyzer and noticed that it's not a very used gun. I think that because the pulsar series makes the catalyzer obsolete.
So here are some suggestions to improve the catalyzer.
Slightly increase the damage (maybe) (weaker than an expanded pulsar shot)
Make the charge shots have a "chain-reaction" effect.
Example: You charge shot 5 enemies each with 1 shot stuck to them. You then shoot a bullet and if the explosion from the charge shot is closer to the other charge shots they will explode too.
I only think the catalyzer series needs to be improved in two aspects: (Biohazard in particular):
1) Anyone notice that the bio's DMG bars and umbra DMG bars are the same? Yet umbra damage does 30 more DMG in tier 3 stratum 3 than bio. (got info from random video). They need to make the bars match the damage.
2) Neutralizer has slightly more DMG than bio, which is normal because of it's effect. Compared to pulsar line however, it is unbalanced. Polaris damage bars are exactly the same as the supernova, yet it has a status effect too. Maybe this is why Polaris is OP....It's not balanced correctly.