.22 Hades vs Jumbo 18gr vs Monster 25gr for hunting

The best choice is whichever is most accurate in your particular rifle, unless distances are so short that a different pellet is sufficiently accurate to place the pellet in the kill zone with as near 100% confidence as you can reasonably ensure. Expansion with the Hades is overhyped based on my testing but the nose profile will produce more tissue damage than a dome. So if it’s accurate in your particular rifle at the distances you will be shooting, by all means use it. Case in point, a conventional wadcutter would be even more effective in most cases...again, provided it’s sufficiently accurate.
 
No, not really. For the same shot placement, a heavy domed pellet and a lighter domed pellet are going to do almost precisely the same amount of tissue damage. The one exception being a shot taken at extreme range...the heavier pellet will retain more energy and penetrate deeper. Seldom will insufficient penetration be a real concern however. Put the pellet through the brain and it’s dropping like a sack of potatoes.

To do more damage, you want either a more blunt nose or a pellet that expands on impact, effectively making it a larger caliber that will interact with more tissue on its way through. 
 
Bigger isn't always better- a pellet that passes through an animal doesn't deliver all of its energy potential.

Remember your Saturday morning cereal bowl after you've eaten all of the cereal? The milk would be red or blue, or if your liver could process that much sugar, brown?

That's left over sugar energy. The bowl of cereal solids you did consume gave your body energy, but there is still more in the milk left at the bottom.

If you vacuum up all of that sugar sludge, you've taken out all you can. A good hp bullet, rifle or pistol driven, can transfer a high percentage of kinetic energy- a solid, non/ little expanding pellet, going all the way through an animal and then continuing in it's Merry way, is taking its energy with it. 

Accuracy, with pellets, is my preferred choice, with energy second- for solid projectiles. If there a pellet that takes all of its energy and dumps it into the animal, you may be able to anchor an animal cleanly with a little less precision. Spend time watching your game's passing into the other side, adjust your aim and desired hold points (and distance), until you can get the quickest possible result. 

Love hunting, been doing it for lots of years ( went out ratting last nite ) but injurying an animal, or seeing pronged suffering breaks my heart. Keep asking questions, share what you observe and we can all learn from each other.
 
A minor clarification, the goal is to expend the maximum amount of energy in the animal. That means maximum interaction with organs, muscle, and bone...thus maximum damage to those tissues. 

All the energy is an impractical goal for the most part. That would only be possible for shots at a singular distance, one type of animal, and one very specific shot placement and angle...say, a shot which runs the pellet lengthwise through the animal’s body so as to ensure it does not pass through (dissipates all its energy). Yet we know that doesn’t necessarily describe the most effective shot, compared to a brain shot that passes all the way through. Placement first, maximizing damage second.