There are a total of 6 weapons in the game. Each weapon has 4 Aspects, so 6 times 4 is 20 different weapons you can play with. That's a lot, but most of the time, you'll want to stick to only 1 Aspect of the weapon. However, it's fun to try different weapons and Aspects though.

Aspect provides a unique ability and/or stats to the weapon. For example, Spear (Aspect of Zagreus) has additional damage, range, and speed up to 25%, while Spear (Aspect of Achilles) provide a unique ability call "Raging Rush".

While everyone has their own favorite weapons and ranking so I'm not gonna provide the ranking list, instead, you'll have to play and figure which one is the best for you. Ideally, when trying to increase Heats (Pact of Punishment), range weapons tend to perform better than melee weapons.

1. Stygian Blade: short range, instead it provides speed and attack combo, but it lacks damage.
2. Eternal Spear: medium range, medium speed, and combo, so it is good overall.
3. Shield of Chaos: lack of combo, but provides good damage and range. The selling point of the shield its ability to block all type of attacks. Many players get higher Heats with Shield.
4. Heart-Seeking Bow: long range, but slow in speed, most of all, it is a single target weapon (unless upgrade with Daedalus Hammer) make it slow for clearing wave of enemies.
5. Twin Fists: short range but it has very high speed attack. It is not viable for high Heats but it's very fun to play though.
6. Adamant Rail: long range, high speed, but lacks damage. It is also a single target weapon (unless upgrade with Daedalus Hammer).