If you don't mind using a hacking tool to **** with cheaters, consider the following tricks:
- weapons with the cursing property edited onto them will always instantly kill anything, even if it has infinite or frozen hp. Always go for the maximum value of curse, in case they have the maximum curse resistance. The only time this won't kill a cheater is if they know how to freeze their status resistances.
- it is possible to add a property onto a weapon that changes what the last bonfire they rested at was (so, the one they'll respawn at). It is also possible to add the Dark Sign effect onto a weapon as an activates-on-hit effect. In other words, you can change the last bonfire they rested at to the Abyss, force them to warp back there, and if they didn't kill the Four Kings and don't have the Covenant of Artorias equipped, they'll be locked into an infinite loop of being eaten by the abyss and respawning. This will last until they use their cheat engine to warp to a different location.
- make your own hp infinite/frozen, freeze your curse meter buildup, and then just stand there and wait for them to get bored. Don't move, don't fight back, just stand there. Go make a sandwich. Your character is now a lesson in the futility of cheating.
- summon the four kings and set their hp bar to infinity. Make popcorn and watch the show.
- People using cheat engines can, and most likely did, instantly give themselves whatever gear they want and nine billion souls with the push of a button. Don't feel any remorse for destroying absolutely every aspect of their character. Weapons and armor? Destroy it. Levels? If you can figure out how to drain levels, do it. Corrupting save files? This might seem extreme, but at most it'll keep them off the game for maybe a minute. Do what you want to them, it's not like they'll ever stop.
If you don't want to use a hacking tool to beat out hackers:
- knock them off a cliff. This works 99% of the time.
- for some reason, dealing an arbitrarily large amount of damage all at once will auto-kill people, even if they have infinite hp. The amount of damage required to do this is far beyond the amount of hp a player can legitimately get, so the only time it will happen is against cheaters. Get familiar with Pursuers, Dark Bead, Power Within, and Red Tearstone.
- unequip all your gear and equip the dark wood grain ring. when a hacker invades, just dodge their every attack. it's important to be more patient than them when doing this, as the goal is to mentally fatigue them to the point where you can subtly bait them to a ledge and dragon roar them off a cliff.
- generally speaking, if you can't beat them the next best thing is to erode away at their willpower and energy until they no longer want to continue. Most people who use a cheat engine are extremely bad at the game, and even good players who start using a cheat engine will get rusty fast. Look up videos of how to chain backstabs, dodge in lag-heavy environments, and practice parrying. Always remember to never, ever "finish". Bait them with anticipation, but never follow through. If you parry them, don't riposte. If you dodge an attack that leaves them wide open, don't counter attack. If you make them stagger with a hit, don't land the next hit. This is far, far more frustrating to the cheater than just pinning them in a corner and not letting them move, because stunlocking them forever allows them to give up. Don't give them a chance to just surrender, let them keep trying and interrupt their attempts to fight, but let them recover from it. This allows you to drag the fight on for much longer, draw out every scrap of willpower in them, and slowly crush everything they have.
- send them fanmail. Keep it normal at first, then get a little flirty, and continue escalating it until you've reached aggressively homoerotic levels of naughty. If they try to flirt back, keep escalating it until they get too weirded out to continue, then keep going. Every time they invade you, type out an RP fantasy of them doing filthy things related to how they attacked your character. Act like you're getting more and more excited. If they never invade you again, you win. Note that this "method" requires some creativity.
Always remember, if an invader is trapped in your world they can't invade other people. Don't let them out until you're done with them.