Lines are quoted from the official notes; buff/nerf tags are auto-classified from the numbers and can be wrong. Covers the 14 most recent Dota 2 patches PatchMeter has fetched.
▼nerfDamage gain per level decreased from 3.6 to 3.4
▲buffBase Movement Speed increased from 285 to 300
✕removedRunic InfusionNo longer grants the Regeneration Rune buff upon activating any rune
⇄adjustRunic InfusionNow provides Arc Warden with +1.5 all attributes permanently whenever Arc Warden or the Tempest Double activates a Power Rune
⇄adjustMagnetic FieldThe field now also pulls runes, and automatically activates ones that are inside. Rune Pull Force: 100. Rune Pull Radius: 800/1200/1600/2000
▲buffSpark WraithSlow Duration increased from 0.5/0.6/0.7/0.8s to 0.7/0.8/0.9/1s
✕removedSpark WraithNo longer upgraded with Aghanim's Shard
▲buffTempest DoubleGold and XP Bounty rescaled from 180/240/300 to 70 + 10 per level
⇄adjustTempest DoubleNow upgraded with Aghanim's Shard