A Skill gone bad

Alright, I need to know how to make a skill similar to Sentinel, but can level up (as it is a hero skill). It also has to be a sort of "self-aura" in that it only effects the hero. I'm literally pulling my hair out over this, because I just can't figure it out.

Anyways, I need it so that there are:
A) No creepy owls.
B) The endurance aura art under the hero
C) Four levels

1) Sight radius plus 50

2) Sight radius plus 100

3) Sight radius plus 100 (no change); can see invisible, burrowed

4) Sight radius plus 150; can see invisible, burrowed

D) Always active

That's what I need, and I'm willing to throw in ten points for the person who answers me if the ywant it (I don't have too many, posting in off-topic and art forums doesn't get me points :\ )

Try modifying the true sight ability.

You're going to need triggers for this also... It's too late for me to work it out though.

I'll look into this if it isn't done tomorrow (which is likely going to be more han 12 hours before I next look at this)

I'll try that, thx.

[Edit:] Well, I might not need this skill, my hero is limited to five skills :\
and here I wanted to do seven....

Sentinell is totally bugged; I tried making a hero skill of it that you could cast on units instead of trees... didn't work. I could target units but there was no effect, the owl scout wouldn't spawn.

This is pretty hard, you need to use a custom upgrade to increase scout range. You might also be able to get ultravision with a custom upgrade. (note that using an upgrade means tomes of retraining cannot un-learn the skill properly)

It is actually very simple. Just detect what the level the useless ability is, then if its level one, create a visisbility modifier and make it something like (Current Visibilty Radius + 100) Then if you want to detect units, just give the the true sight, but hidden, or just give it to some aloc unit that is locked to the hero... o_O

Well, thanks for the boatloads of help all, but I'm afraid this skill is a total flop; it would greatly unbalance gameplay in my map. Again, thanks anyway.

Well, an unbalanced map is... well it's ToB!

lol now that's funny. Anyways, you all may be able to help me yet! I need to know which event to use when the trigger initializes when the defend ability is clicked. Any takers?
Ok, now that's bringing up problems in itself. I'll need this one solved before I can start on the one just above this one.
I have a custom ability (Check Hero Type) that is one of the abilities of a custom unit (Hero Information). I have a trigger that gives that unit to a player when he/she selects it, and takes it away when it is deselected. The only problem here, is that the skill "Check Hero Type" (based off of defend) doesn't show up as one of the clickable buttons for skills. Can anyone tell me what's going on here?

Did you use ability defend or upgrade defend?

Based on ability defend, with required upgrade removed.