Actually, Lapras only needs 2 DDs to do tons of damage. It takes away about half of Milotic's health after 2 DDs. With Life Orb, I'm pretty sure it's a 2KO. Also, you never see Feraligatr setting up on Milotic. HP Grass just barely breaks the standard DD sets sub (does like 28% average). With some sp. def. EVs it can set up on Milotic. Spikes aren't even common in this metagame anymore, and I'm using a spinner with it. Hitmontop can't bother with it assuming its behind a sub and at +1 which is often the case if you switch it in on Registeel. Same applies to Spiritomb. Rotom can't bother with it either under those conditions as it's outsped and 2KOed.
Bulky Grass types are really its only obstacle. Note that it does 2KO bulky Venusaur with a +1 Return, though and this isn't assuming Life Orb is held.
- First, you assume a +2 Lapras, which no reasonable player will allow to happen, unless they have ran out of counters (which is hard on stall) or missplay, which are things you cannot rely on.
- Sub + Life Orb is absolutely contradictory, as it's Lapras' very same bulk that makes it remotely viable.
- Milotic could give less of a damn if Lapras is setting up, as it'll just have its boosts hazed away when it gets to +2 (we're assuming stall here, and no one would run 3 attacks unless they are pretty sure they got everything else covered); while it doesn't hit back for considerable damage, differently from Feraligatr.
- You're using a spinner, which means this perfect stallbreaker needs some considerable support to do its job; and you've been talking about stall all long, so Spikes are to be assumed and so is spinblocking.
- I repeat again, no player is gonna let you get +1, Substitute and then bring in their Hitmontop. People know what sweepers are capable of and will switch to their counters as soon as possible not to be swept, and Hitmontop's Intimidate + continuous Close Combats will force Lapras to lose a lot of HP subbing to win
- Repeating, Lapras will have a Sub OR have +1 status, not both.
- Registeel isn't common on stall, but balance.
- Regarding Rotom we have the following situation: Lapras switches in; Lapras uses Dragon Dance as Rotom comes in; Lapras doesn't OHKO Rotom while said floating poké either burns it or hit it with a STAB Thunderbolt; Lapras loses. Same applies to Venusaur;