Suships are an incredibly fun and strong XYZ-spam strategy. They excel at special summoning themselves and accruing more advantage while doing so. They have a lot going for them in that every extra deck cards has multiple strong effects, they have insane crackback power/potential, and they have an amazing boss in uni super dreadnought who can target cards up to the number of suship extra deck monsters you have and negate their effects forever.
The main issues arise when you realize that every single one of the extra deck suships effects are conditional upon what they have attached to them. This makes them very difficult to play optimally. On top of this, the super strong effect of uni super dreadnought can only be used during your main phase or your opponent’s battle phase, hindering this super strong effect a lot.
To compensate for this people have tried many things from mixing them with time thiefs to using it as a zeus engine (as uni super dreadnought can attach directly). I have found, however, that a control variant is the most optimal way to play suships. This is because every extra deck monster draws you a card as long as you use a shari to make it, giving you insane value and advantage.
Things that are not optimal about my build:
Kaijus - While I like them, Kaijus are not the best. I find that they are only good when your opponent only gets out one towers and you can flip gozen on them.
Chaos Hunter - So we like to disrupt with banishing... but we also don't want to get runic murdered... This single card is necessary given the current landscape, but be careful when siding as it can mess up your shifter.
Things that are optimal/cool:
Ice dragon’s prison is actually amazing in the current format, being able to shut down most boards and absolutely ruin a tear players day
Megaclops is an amazing towers that works super well with this deck
Shifter is wonderful in this deck for the same reasons its great in exosisters
Carrier’s attack gain ability stacks :) (this is why it is the only one at 3. Because it is objectively the best)
Fissure is a wonderful addition to the side. While not the best, It is still very good and can impact the game very favorably/slow it down to the point where you can go unga-boonga and bonk with big ships.
Things I would change to make more optimal:
Prosperity is an amazing card that I do not own. If you own it I would recommend swapping anti-spell for it.
At the end of the day, I would suggest this deck as it is relatively cheap and insanely fun. I would recommend reading all the shari cards as many of their effects are actually 2-3 effects in one and understanding them separates the average suship captains from the admirals.