Currently, I'm using:

Mystical Star Shuriken Wolfslayer Malevolent Grimfruit Bottled Dark Matter

My stats are: Level 1005 Health 2001 Strength 1645 Defense 1005 Speed 1016

If someone could recommend just upgrades to what I have, which will one-hit kill and heal (I'm no good at tactics, I'd rather just get in and out, no mess, no fuss) that'd be amazing.

Thanks in advance. :)

I'm afraid that you'll have to wait for a looong looong time if you want to only one hit kill opponents. For example, my tier 7 pet can kill Fish Breath Jaques a couple of times, but my tier 12 pet still doesn't one hit kill him. Your pet has outgrown your weapons quite a bit, if you improve your set, you'll have no troubles beating some more opponents without much effort. I'm not very good at giving advice for tier 9, I don't really know a lot about the weapons of that tier, since I mostly use tier 8 weapons which I have. The Malignant Rift Staff is a good options since it scales, and becomes really good once your pet reaches tier 11 because then it starts to heal. So that's more of a long term investment. If you're more interested in weapons that are good right now in this tier, then I'd probably go for Bludgeon of Mass Extinction and a Blessed Trident of the Banished One (also a scaling weapon). If you think the trident is too expensive, then take a look at the nice tier 8 weapons available: Large Gutting Knife and Purple Spider Squeaky Toy. Also Rapier of Error is nice for it's curse and chance to freeze your opponent. Though it doesn't have any defensive capabilities or healing to it, I still use it on my tier 12. Besides two main attackers, most people also have one freezer and one or more healers and one or two full blockers. The full blockers (Shinwas Temple Shard and Rainbow Vortex) can be a bit expensive, so I'd advise you to at least invest in one healer and a freezer before you start saving up for those. The most widely used healers are the Phoenix Quill (heals 100% of your pets hp once per battle) and Reviver of the Lion (heals 70% of your pets hp once per battle). There are plenty of freezers to choose from, so which one you pick is usually decided by your budget or the opponent that you're fighting: Gorgun: 100% freeze once per battle Gate Keeper Collar of Slavery: 100% freeze once per battle and deals some light damage, defends some physical damage Siren Harp: 100% freeze once per battle and deals some water damage, defends some water damage Deluxe Death Shard: 100% freeze once per battle and deals some dark damage and has some defense against dark Simple Catoblepas Wheeley Toy : 100% freeze once per battle and deals some dark and earth damage Scientist Specs: 100% freeze once per battle, deals some various types of damage, defends water and light, boosts the pets stats for the remainder of the fight Intricate Energized Helmet: 100% freeze once per battle, defends mostly light, activates a blessing that prevents you from being frozen for two turns

After you got the opponent frozen, you could use a bomb to deal tons of damage in that one turn. As your pet grows, these bombs become somewhat less usefull though. Acorn Bomb and Item Hunters Bomb are nice, though I'm not sure whether you can use them both in the same set (I think the stats on them are reduced if you got them both, but I'm not 100% sure on that)

Then I'd reccommend that you look into the Soma Tablets. That's a very tactical use item, but it will help you tremendously if you try to beat opponents that your pet is a good match for. It will turn one of your opponents weapons into something useless, so on the turns that they use it, they deal a lot less damage to your pet, or heal up a lot less.

Are you using any scrolls? If you like bombing stuff, then Morosbane is for you. You can only use it once per battle though, so I'd reccommend getting at least one infinite use scroll, and preferrably one that heals. Terra Focujin is great. A cheaper healing scroll would be Divine Denizhen or Soothing Current. You can make these three healing scrolls at the secluded shrine, so no need to buy them off the shop search if the materials are cheaper.

Don't forget to put mods on your weapons! Most people use Natural Armor crystals (protect against stealing and give some defense), Parched Baguettes or crystals (protect from being frozen), Critical strike tear crystals (give your weapons a chance to apply critical strikes that do double damage) or Singed Baguettes (deal some more damage and activate a curse that deals some damage) on their main weapons. The once per battle items don't matter so much, I think I either put some damage mods or the singed ones on those, altough critical strikes on bombs can be pretty fun too.

I hope my chaotic overview helps a bit, I'm never good at structuring my adivce :P

Thank you so much for your help! I admit to still being confused, but it really helped, and I've more than doubled the damage I can do now, so thank you! :)