First, to the positive qualities of sick people.
He starts with +12 max HP and gains +25% life steal from the start.
The negative traits are that he takes 1 damage every second that doesn't grant invulnerability and that he starts with -100 HP regeneration.
On this character, we're going to make use of the very high life steal, using weapons that attack multiple enemies at once, so that from that same stat, we're going to trigger a life regen, that will exceed the 1 damage per second.
To do this, we begin the run with the slingshot.
At the beginning you will notice that this one weapon, despite the fact that it bounces off another opponent, is not enough to compensate for the damage automatically suffered.
However, the increased max. HP is enough for the first rounds so that you won't die as long as you don't get hit too often.
Get more slingshots and keep an eye out for more items that give you more regeneration, such as the cute monkey.
With this item, you should get a significantly increased life regeneration, especially later in the game, since there will be more opponents who will drop more materials.
Of course, the damage must not be neglected either, otherwise it will be difficult to destroy the opponents in time to get the materials in the first place.
Get Ranged Damage, % Damage, and most importantly, Attack Speed to allow life steal to proc more often.
Crit Chance is also very good as it will increase your damage even further, albeit with a chance.
Get defensive mostly armor and max HP and maybe some dodge and speed.
You can ignore the pure life regeneration here or reduce it further, since the negative value can hardly be compensated for from the start and is therefore not worth it.
A bit of luck can also be very helpful here, as it gives enemies an increased chance of dropping items that heal you, and you can always pick them up in an emergency.
If you complete the run successfully, you will receive future access to the whetstone, which is a very good item for most other characters as well.