At the moment, this mod adds 2 power tiers, 2 powers, 1 structure and 3 mobs.

Press the "=" key for an in-game tutorial, NOTE: it may not be the full tutorial.
If you want to see what the mod adds, look here:

Mod details

Mobs:

Slightly Dragonified Skelton:

Use Dragon's Breath on a skeleton to slightly dragonify him. The mob sometimes shoots dragon fireballs when hurt.

Upgrader Helper:

Spawned by the Helper Spawner item. Passive, gives growing thorns effect to player which acts like thorns armor. In addition. gives negative effects to spiders and cave spider.

Spider Lord:

Boss of the Spider cave. This boss has the ability of flight, and summoning of spiders. He drops the fabled tier 2 withstander when killed.

Structures:

Spider Cave:

Spawns at 0, 0 low in the overworld, above it are 2 spi-wners (Custom Spider spawners) that spawn a cave spider and a spider when a player is nearby. Another new block is found called the "spi-door" (a spider-based trapdoor.) Currently only one of these structures spawns per world.

Powers:

Tier One:

To begin, craft a Tier 1 withstander block. Craft a Healthstealer to hit a mob to steal health. I recommend that you craft a stolen health meter to measure stolen health by right-clicking. When stolen health is 12 or higher, right click the tier 1 withstander block. Then a tier 1 withstander helmet will spawn high up in the sky, the block will get turned to gold, a blaze spawns. Wear the helmet to withstand tier 1 powers.

Flying tool:

after you have crafted it, right-click to fly! Note: this works mid air.

Helper Spawner:

Right-click to open a GUI, then click the helper you want to spawn, make sure you have a diamond block in your off-hand.

Tier Two:

To begin, kill the spider lord, he drops the tier 2 withstander.