I don't think enough credit is being given to how powerful this combination is, and it is primarily because of the mana returned (total of 2700) and not the health regained.
Since you will rarely ever need more mana than your opponent has health, Oak using sheild+heart of life is able to completely ignore his mana pool and focus instead of health items, since he can regenerate (and cast) all his mana while doing this trick. In effect oak is capable of obtaining a bonus +600 or so health from the slot he saved on not using a mana item on top of his already high health, then an additional +1800 from the heart of life, and a mana pool that will always be large enough to defeat his opponent.
Mid game when health totals are 3-4k that extra 2400hp is enough to win any 1v1 combat. However, this isn't taking into consideration the 6 seconds of invincibility that saves him approximately 600-1200 health from autodamage (more if against multiple foes) and completely prevents any spike damage. What this means is that oak can often engage 2v1, defeat an opponent and then escape.
That doesn't mean there aren't counters to this. Ironically you mentioned that you were playing torch bearer, which is one of the banes to this strategy. Deep freeze increases cooldowns by approximately 130%-220% for 5-8 seconds depending on it's rank. The increase to cooldown is caculated on the 'base' and not 'current' ammount. In other words.. if sheild has a 30 second recharge, and he used sheild 45 seconds ago, casting deep freeze (even rank 1) will stop him from using it again for the duration of deep freeze. Even if oak manages to activate sheild, you can still use this on him to shutdown his ability to use the heart of life.
This guy pretty much speaks the word of god to me...
PLUS EVERYONE LISTEN TO THIS
I JUST PLAYED A GAME WHERE AN OAK USED WINGS OF SERAPHIM AND HOL!!! HOW IS THIS NOT SUPER OP.
He pretty much had an instant around 3500 health EXTRA plus mana and as said above oaks mana is totally worthless with it. Theres no need to worry. Expecially if you get some 70% extra mana per second that works on HOL and make him restore all of it.
Any DG can use HoL and if you don't know how and when to get away from battle you don't know how to play Demigod. So step away and heal, and be back into battle within seconds. Works for pretty much any DG with HoL. Don't confuse Oak's strenghts and overlook his weaknesses based on a popular, possibly in need of rebalancing item.
Quoting StAcK3D_ActR,
reply 19
...
Oak Invincibility
is a very cheap spell.
So is Rook Towers, Spit, Snipe, Bramble shield and I'm sure a bunch of others...
But if i'm correct he can use it incombat uninterupted. And bramble shield is only good begining of game and while QoT has mana. Spit is good but not OP. Snipe of course is good but not anything differant from spit and fireball. It just gives regulus and assist or kill neting him gold. He's not a very good creep farmer and actually tends to underlevel (when not using mines). All of these people have this as a PURPOSEFUL skill while Shield+HOL is a combination of a spell and an item, an item which a lot of people get anyway so it isn't uncommon, making it BETTER THAN those others. All those cost mana all have casting time (except towers and bramble) but none RESTORE health and grant temporary invincibility and regen.
Yeah but people still complain Actually I don't think any of the above spells is realy cheap.
Example, I tought spit is extremely OP early for chasing you out of a lane and giving UB such an advantage that it was impossible to contend. Seems I just needed to learn to work against it... pretty much like with everything else.
Agreed some balances wont be fixed but when the REALLY big things like regulus getting early mines (which i think is only op in begining i'm not one of those people totally against it). At level 7 he can dish out 1500 burst damage every 8 seconds or so. But this is an easy fix and normally someone focusing on mines as said above underlevels for the begining portion of the game. Plus they sacrifice for mana items instead of health and damage. But Oak invincibility is AN ACCIDENT it wasn't balanced at all it was put in there by accident. All people have the ability to escape and use HOL is true. But WE ARE TALKING IN COMBAT PEOPLE. Sure its no differant than a pot but a pot can be interrupted expecially the 2 second ones. Sedna's heal was meant to be in the game and it costs mana it doesn't give it.
EDIT-
For all of you who read this WALL OF TEXTING thank you. Thank god most of it is quotes so you didn't need to read as much. If you read the quotes get yourself a cookie. 