Blastoise is great, it has great defenses and is a great spinner. It also has acces to scald like all water types but compared to the others it is the weaker tank. Although it has great defenses, it can easily get 2HKO by an electric or grass type move whiles the others have acces to reliable recovery moves
Advantages
- Great Defenses
- Reliable Spinning
- Can induce a status move (Scald burn or toxic)
- Phasing moves (Roar, Dragon Tail)
Disadvantages
- Lacks a recovery move
Well tbh, in my opinion Milotic is your best bet. It has great bulk and can tank special hits until you bang your head on your desk. Not to forget that it has acces to a reliable recovery move something that 3 if the 5 lack. It can haze and or phase and or stall to death with toxic and has enough speed to accomplish reliable recovery.
Advantages
- Great Special Defense
- Reliable recovery move (Recover)
- Status inducing moves
- Phasing moves
- Stat-resetting move (great to block set-up sweepers which means that Suicune can be stalled to death when running calm mind)
- Decent speed stat
- Defensive boost when affected by Sleep, Paralysis, Burn, Poison
Disadvantages
- Doesn't take physical attacks as well
- Is rendered useless when taunted
Slowbro is probably one of the most annoying water types to get down due to it's great typing and ability. It's typing is great but renders it weak to many threats such as Gallade, Scrafty, Yanmega etc...Like Milotic it has acces to a reliable recovery move. Not forget it's formidable bulk. With regenerator it can switch out with ease whiles recovering a buch of HP.
Advantages
- Great Bulk
- Reliable recovery move
- Great Ability
- Acces to status inducing moves
Slowbro and Milotic are very similar to eac hother
Disadvantages
- Is rendered an easy bait when taunted( it can always switch out if needed)
- can't stop set-up sweepers (only with scald which is really unreliable)
- Typing renders it weak to grass, electric, dark, ghost, bug. This makes it very easy to bring down when it isn't used properly
Swampert is an excellent Tank that can take many hits and hits back very hard. Probably the hardest out of the 5. Though it must be wary of grass types more then the 5. It has acces to many moves that give it coverage. It's biggest bonus is that it is immune to electric types, a prominent weakness that many water types fail to cover.
Advantages
- Immune to electric
- Broad movepool
- Acces to status inducing moves
- Great bulk
- Great Attack
Disadvantages
- Is horribly weak to grass
- Has low speed meaning that it can easily get 2HKO'd if it fails to KO the threat on the first turn
- Lacks a reliable recovery move which makes it easily outstalled when facing the others.
Suicune is uber bulky but calm mind is it's crutch. Compared to Milotic and Slowbro it is the weakest against taunt since it really relies on it. Other then this it is very impressive as it can just rest itself out of any status inducement. Making it almost impossible to outstall. Although I favour Milotic and I think Milotic will be the most useful, if you want a prominent wall Suicune is very fine Pokemon to pick :)