I seriously do not understand the hype around this unit - on this tierlist, he's ranked as being top ten. I don't disagree that he is definitely better than a lot of ubers, but considering how much you have to grind to obtain his true form, it is really disappointing that he has the same health as Mecha-Bun, which is widely clowned on as one of the worst legend units. Most of the time, he still struggles to get a single attack in, and even when he does, if he doesn't activate a savage blow (which is only a 30% chance), he only does around 200,000 damage, and considering most end-game bosses have millions of health, it's not super helpful. Yes, it's neat that his recharge is fairly quick, but considering how expensive he is, you will still struggle to send him out a lot of the time, and if you have the cash to send him out, you probably have the cash to send out lots of other stuff anyway.
It is nice that his true form has as many immunities as it does, and I can definitely see some niche usages for those. But the fact that this unit is considered better than ubers like Mitama and even D. Lunacia is ridiculous, considering both of them make a difference in just about any stage that they are brought into.
In short I see Lasvoss as just a shittier Kai with more immunities and would rank him in B tier at best and probably a lot lower than that when accounting for how much grinding it takes to get his TF, and personally, would only ever use him for that one cat combo.