Oh, and it flies. Well, Super Jumps, but with 6-4 movement and an S7 Silhouette for vaulting it feels like its feet barely touch the ground.
A Seraph wields a mere Spitfire as its primary weapon, but at close ranges that is preferable to the HMGs of most TAGs. With BS15 the Spitfire is still entirely usable at long range, but only reliable against weak enemies.
Super Jump allows you to attack from unexpected angles, often targeting troops your opponent thought were safe at the cost of forfeiting your own cover.
The Auxbot serves as a disposable flamethrower, or complimentary threat: an enemy which is dodging the flames isn't shooting your TAG.
The nanopulser has occasional uses in the active turn for guaranteed hits on enemies with extreme penalties to hit them, for Intuitive Attacks on markers and other usual template tricks, but usually you should just shoot with the Spitfire.
Despite the size of the model's sword there are very few cases where using it is a good idea. Being tied up in melee tends to be a death sentence for any TAG, and CC20 isn't enough to change that. Perhaps it could be useful against an enemy with ODD with the bonuses from engaging with the auxbot too, but the sword is primarily useful for hitting destructible objectives. You can't rely on beating an enemy who's competent in melee at their own game, and should usually simply Spitfire them instead.
The Auxbot can often be used like a mine to discourage attackers. It can also potentially be used to block thin passages and force enemies to spend orders finishing it or leave cover. But be careful of enemies using it to hit the TAG with Impact Templates from out of sight, especially with missiles.
The Seraph's melee ability may not be enough to justify attacking with, but it helps convince enemy melee troops to stay away: they won't have as great an advantage as usual, they'll have to get through multiple ARM7 wounds, and a single win for the Seraph will probably kill whatever attacked it.
Super Jump lets you pull off shots into troops your opponent thought were hidden, and so are facing backwards or otherwise exposed. Despite being a light TAG a Seraph still has the full size Silhouette 7, giving the ability to vault over a surprising amount of terrain without even using Super Jump; but after vaulting onto a building and then jumping up to 6" diagonally upwards you can see almost whatever you want. Unless your opponent has specifically planned for Super Jump when deploying they're likely to have left important troops exposed on rooftops; and if they avoided these spots then their deployment is restricted, which is also useful.
Remember that you can't use Coordinated Orders on a Seraph while its Auxbot is active, and the rules aren't yet clear if you can once the Auxbot is down. So repositioning at the end of your turn can't be combined with the other movements you need to make.
Snipers and missiles can pin down a Seraph surprisingly easily. And at the short ranges a Spitfire wants, hacking and melee are relatively easy to bring into position.
Seraphs are PanO's cheapest TAGs, and so slightly less of an investment. However they're not very effective as a primary sweeper, so you'll need something else for that role.
As with other TAGs they need support in order to survive, but there are cases where a Seraph can just be thrown into an enemy flank with no expectation for it to survive. If it is intended as a disposable missile then support may not be essential.
All the usual TAG support applies to a Seraph:
An MSV2+ troop to cover the TAG and prevent enemies using smoke cover to reach melee, preferably a sniper.
An engineer for repairing wounds, although this is less useful for a Seraph than for most TAGs because an Unconscious Seraph is likely to be stuck deep in enemy lines and out of reach.
Hacking to preemptively kill enemy hackers and/or re-possess your TAG.
Something to rescue your TAG from melee if it's engaged at the start of your turn. This can either be a melee troop or a high BS gun: shooting into melee a hit is more likely to kill the melee expert than to even scratch your own TAG, so even odds of hitting either troop is often acceptable.
A Seraph usually shouldn't be deployed with much line of sight, because they're poorly suited for making long range AROs, but where they can advance quickly up a part of the table where all the dangerous enemies they see would be within 24".
Remember that your Auxbot doesn't have Super Jump. While you can leave it behind, you don't want to do that accidentally.
Active Turn Role
Carrying a Spitfire instead of the HMGs and larger weapons of most other TAGs suits the Seraph to charging forward to clear ground. On the other hand a Spitfire's shorter range makes a Seraph surprisingly ineffective at sweeping away enemy snipers and other dedicated AROs, so leave that role to your HMGs.
Seraphs are not great for AROing compared to other TAGs. A well positioned Suppression Fire can be highly effective, but generally a Seraph should try to hide through the reactive turn.
Consider whether an attacking enemy is lightly armed enough to risk unopposed hits from in order to fire the nanopulser.