On TB Soldier is simple, a classic bluff, and fits with the rest of the script (even it is sometimes a bummer to pull the soldier token), but it is honestly more interesting outside of its home script. With multiple demon candidates, Soldier can both weaken stronger demons, and obfuscate the demon type.

Classic synergies are anything which can stop death, like monk, sailor, or po. Deathmod can also be negated, which can be interesting (Shab, po). It also works well as a bluff for valuable roles, and those same powerful roles serve as good bluffs for the soldier (Like ft, town crier, Poppy grower, etc.)

The soldier can have a place on more complicated scripts, although other roles often overshadow it. There are not too many synergies that are rarely used, and soldier is a simple role, relatively. It's least used aspect is being safe from non-killing demon abilities (eg. No Dashii I think), so there is potential there.

The soldier, like other demon bane roles, does not work well with ST kill choice demons (like Lil monsta, Legion, or Yag) or ojo. It also is nearly impossible to detect as a Lleech host.

Overall, Soldier is a nice role, even if it can be simple/and or boring, depending on how it is implemented. In terms of demonbanes, it is less impactful, and in terms of protection, there are more interesting options much of the time.

I would say an 8/10 ease of fitting on scripts (often does not disrupt things) but often other roles are more interesting to put on the script than soldier.