Item Ideas

Should I remind you that there is a limit for your HP5? well that's 100. Couple Shield of Regrowth with Stone/Gem of Gaia and you have yourself 100 HP5 when you get hit by an ability for a certain duration.
As for the enemies, they can handle without their HP5 for 5 seconds, believe me. Actually now that I think about it I'll change it so that if you hit multiple people at once with the same ability, it only steals the HP5 from the god which has the most of it and that you can only steal HP5 from one god a time. Applies to Sorcerer's tome as well.

ok, first off, I assume that you can steal as much as you want since it would be silly otherwise, and I mean like "You can only steal the health of any enemy every [insert fairly high number]s" so that you can't constantly steal someones HP5

you steal 50% of their HP5 every time you hit them, stacks 2 times and lasts 5 seconds.
Now in smite you don't constantly attack an enemy. And if I'm not wrong, HP5 means Health Per 5, so you only steal 1 proc of the enemies' HP5. I don't understand what is so wrong with that, not all players build up HP5, and it isn't such a critical attribute in combat as movement speed/attack speed/power.
Also, Brawler's Beat Stick and Divine Ruin reduce the target's healing and regneration by 50% for 3 seconds. That means that their HP5 would have 50 effectiveness and heals as well ehich against certain player (Hel, Ra, Cupid, Chang'e, Guan Yu etc.) is extremely useful. And on top of that it grants you lifesteal. That is quite a similar effect and nobody complains about, because they shouldn't. Getting some HP5 from yoyur opponent for 5 seconds won't brake the game at all and is a niche item that could severe well.