So, for using that sword you want places that benefit the energy part of the weapon. First things that come to mind are Banuta and Medusa Tower for me. At your level you have to be careful on both of those spawns not to take too many medusae though as they can beat you pretty badly. Always wear garlic necklace, maybe even swap to deep if you take too many.
If you still feel like those nasty serpent spawns&medusae are too hard, you can stick to hydras. The oramond spawn is great for EKs in general but the gnome sword makes it even better. From my experience sticking to the outer circle on both floors nets the best experience.
Another spawn that i found really enjoyable using the gnome sword was grim reapers! At level 200 the yalahar spawn is really nice experience and can even proof profitable at times. The strategy involves using fire walls/bombs and standing on them so only 3 grims can hit you with only 1 hittng you with waves/beams. Start slow and try luring 2 maybe, if that works well get a third. Be prepared to use health potions when you hit yellow, they hit hard.
Just thinking about it, where do mages use thunderstorms? Oramond west! You can rip tons of experience there and the sword really benefits the spawn as pretty much everything is weak to energy. Full imbues recommended as you are still fairly low, but its doable.
Going further into that, which monsters are the most beneficial there? It's the quaras! Heading towards calassa might be better than ever before (+ you might find yourself a nice new mount? Chances are there!) Don't get swarmed there as they actually hit pretty hard (way harder then the scouts you encounter on the surface of oramond west).
In case the catacombs on your server are filled with golems they are a viable option aswell! Duo with a druid is probably better than solo at this point but if you start slow to get a feel for it and don't take 8 (5 should be fine) you can probably hunt there solo aswell.
This is far from your level (probably 350~+?) but the gnome sword is also the best weapon to take when you are going to hunt either plagirath or jugg seal in ferumbras ascension area, so heads up! You can look forward to that.