Early Spirit usage in Super Smash Bros. Ultimate might involve going with what is immediately necessary in World of Light. Someone might just go with the highest rank Primary Spirit on their team to get started, so there is someone strong and with a lot of slots that can provide the automatically suggested assistance to overcome certain stage hazards or situations. But the way the game is executed, every Spirit can be valuable.
A lot of this is due to the Support Spirits that can be added to a team. These are the characters that, for between one and three slot spaces, can provide all sorts of amazing bonuses to improve your chances of succeeding. Two of my favorite teams focus on survivability, which means they are useful in World of Light or if I happen upon a regular Super Smash Bros. Ultimate match where Spirits are allowed. i have a healing team that involves having a Nightmare Ace-level Primary Spirit and Great Fairy Ace-level Support Spirit. The former has a Lifesteal ability that restores health when I strike a foe, while the latter’s critical Health Healing restores a lot of health after a lot of damage is done. Similarly, I have a team called Reflect & Regen that has the Ace Father Balder with a projectile-reflecting Franklin Badge equipped effect and an Ace Meloette Aria Forme Support that bestows the Autoheal effect that adds a regenerating effect every five seconds. Both of these setups work with any sort of character to provide a little more survivability and security.
There sorts of Spirits also can help you have a good team that makes sure you are a solid heavy hitter in a match. Plenty of options are available, because there are so many incredible characters out there. One that I found that can be handy is having the Ace Petey Piranha Primary Spirit set up, since he makes a character gigantic briefly for the first moments of a round. I really like how this pairs with the Star Rod Ace Support Spirit. This gives a First-Strike Advantage that makes you temporarily invincible if you get the first strike in a fight. By having these two together, you can get some early hard hits in, while also becoming something of an unstoppable force.
But, for a really great general team, I like adding some strong supporters to the Legend Wolf Link & Midna Primary Spirit. This one has three slots and a Dash Attack increase that makes you faster and increases dash and tackle attack power. Given the strength of the duo, anything can work. But, having the Legend Wind Fish or Shine Sprite Support for their Special-Move strength boost, the Legend Sheriff to aid in killing Assist Trophies, and the Mario Tennis Aces Mario to give my fighter a 5% chance at a critical hit.
These Spirits are at their best when you have a chance to create teams for specific people. The M. Bison Legend Primary Spirit offers a PSI Attack boost for Lucas and Ness. This gives someone a chance to create a team dedicated to making their special attacks even more effective. Someone like Snake or Mii Gunner can be helped by Roll Caskett, who increases shooting attack power. So even though she is only a two-star Spirit, she can be a big help. (Especially if you add her to Revolver Ocelot, who has the same trait, as the ability can stack.) The Legend Akira Primary Spirit is great for Ken, Ryu, or Mii Brawler, since he boosts fist attack power. (Chun-Li is another alternative for a wider audience, since her ability just boosts general physical attacks.) As someone who relies on a lot of Fire Emblem characters and Mii Swordfighter, ProtoMan.EXE and his sword attack boost is great.
The Super Smash Bros. Ultimate Spirit situation is handled in a way that can make lots of characters useful. Their rank may not matter, if the ability they offer suits a character or situation. There are even specific Spirits that play well with certain fighters, adding value if someone is your main. The game handles them well and in a way that it can go beyond fulfilling a "catch ’em all" mentality or attempting to acquire Spirits from series you like. Each one could end up benefitting a player, which is really great.
Super Smash Bros. Ultimate is available for the Nintendo Switch.