Ok so Ihave been quarreling with the idea of using restoration in my Mage character, but other than healing is there any other useful things it has available? And what's the master quest for it make available for the player? Opinions are well appreciated cuz idk if I want to invest perks into it or not

There are the new spells from Dawnguard. They seem weaker, but the "sun" spells against vampires will not hurt anyone else. They are stronger if dual casted. Plus there is the necromage perk, which makes spells that have a duration, last 50% longer, and those that have a magnitude are 25% stronger. This helps makes flesh spells last longer and destruction spells stronger.

If you're going to be a vampire, you can use it in combination with Equilibrium to restore all your Magicka in the sunlight in short order, using only a couple of perks.
(Trade 50 health for 50 magicka, use about 10 magicka to regain 50 health or about 15 to get back 75 at higher levels and repeat)
There's also the famous Necromage vampirism trick and you can use the Respite perk to sprint forever, which is nice for getting around.

The follower-healing (or possibly Dead Thrall healing with the Necromantic Healing spells the Volkihar have in Dawnguard) can be handy, too.

Since a lot of Shouts count as spells, Necromage vampirism also makes, for example, Slow Time have a much longer duration.

Oh ok so then there is a very good reason to invest in restoration for a destruction necromage. Also what's the deal with wards? Are they even useful in battles?

Well, there's a perk that allows you to regain magicka when they're hit by enemy spells.
I haven't used them much, as on my only Restoration character, I have the Block perk for elemental resistance and use that instead, not tp mention being armed to the teeth with anti-magic Alteration perks.