Each weapon comes with one or two main abilities that represent their original owners:

Perun's Axe: Weather Manipulation (Control the weather with great skill like other sky gods such as Zeus and Thor) and Resistance towards Electricity and Cold.

Neptune's Trident: Underwater Breathing, Water Manipulation and Aquatic Life Companionship (Basically Aquaman's Powers).

Surtr's Sword: Fire Manipulation (Conjures flames capable of harming gods and scarring immortals) and Fire/Heat Resistance.

Cronus' Sickle: Flash-Forward (Cannot return to the past) and Time/Age Manipulation (Anything cut by it will quickly age until it crumbles to dust).

Regardless of choice, you'll be reborn as a Demigod which makes you a ''Lightning Bruiser'' and have traits like Decelerated Aging, Superior Regeneration (Including Disease Immunity), Linguistic Assimilation and Supernatural Detection. Another feature, is that you weapon can be called from a distance similar to Mjölnir.

I would reforge the Cronus sickle into a polearm of some kind like halberd or naginata or maybe even a war scythe