Which prostetic tools are the best? Are there some that do more damage than others beside those stronger against certain enemy (axe + shield, etc)
-Flame Vent is good as it provides opening for additional hits on top of DoT. Prior to living force (or against targets that have better resist), use oil first. WIth living force, the gap between attack is smaller since you will likely cause burning on a blocked hit, which generally equates to 2 additional hits from there. You can blow out about 1/6-1/5 of a boss' vitality in one string on NG with difficulty modifiers. By far the most damaging for general purposes.
-Firecracker causes significant stagger, generally regarded as strongest tool.
-iron fortress provides deflect without really needing to pay attention to timing, and additional resistance against terror/fire depending on version chosen. Extremely useful again enemies using predominantly flurry attacks when difficulty modifiers are active, as well as terror/fire enemies when needed.
-Mist Raven is a different way of creating large gap, as enemy doesn't de-target from where player character was for a few seconds. It is also good for getting out of a corner if that happens. Most importantly, any upgraded variation allows for extraction to safety when hit, making it invaluable when fighting multiple enemies, or even against a regular hit if you don't want to get caught in follow-ups.
-Divine Abduction makes it easier to thin out weaker enemies, but it has significant weakness in its start-up (prep into activation is a long time). However, with living force, it becomes much more useful by turning the effect into on-hit at the expense of more or less becoming single target. Extremely invaluable in 1vX.
-Shuriken is just generally useful by virtue of being the only long range option available. Upgraded version also does chip damage which allows for ability to safely finish enemies at range. Chasing slice allows for reliable gap closer.
-Axe is situationally useful due to its slow speed. Outside of shield enemies, they are still strong against certain enemies, but overall it is comparatively lacking in my opinion. Fang skill isn't that great, but the spin to win component that can be spammed is pretty good at expense of being really pricey.
-Spear is situationally extremely useful, but its unique function is underutilized in the game. It's a mid-range replacement for shuriken that's slower but stronger. It has the most diverse upgrade path with sweep and thrust versions. I personally couldn't find too many situations where I'd like to use sweep, but spiral thrust is something I used a lot in certain areas. Its final upgrade is extremely lacking, unfortunately.
-Sabimaru is probably the weakest tool in the game due to poison being a weak status, but it is extremely powerful against a set of enemies. Outside of that there isn't much of a reason to use this particular multiple hit skill, especially now with how good passage combat art is.
-Finger is really just for two uses in my opinion, so extremely situational. I personally really like mountain echo for a couple of instances in the game.