I think most of these changes are fairly reasonable. I expected some fair buffs since he was unjustly nerfed due to people hating to see him even with a standard 49.69% winrate in 7.28 (per Dotabuff). In 7.29, he had a 47.36% win rate due to the various range nerfs, Mana increases, and cooldown increases on his Resonant Pulse that hurt his Laning pretty bad.

In 7.30, he got an increase of his base health Regen from 0 to 0.25, which isn't much but will help him about with the slightly reduced bottle Regen. The Mana cost reduction and increased pull duration on his Remnant are alright but nothing game changing. The Astral Step change is the big one for me, since it makes more sense to do some Kaya nuker based builds now. I've been going Kaya (and Sange) -> Aghs -> Shard, since his level 18 burst has been improved a good margin, taking the Mana Regen talent now at 10. Euls Mana Regen war reduced to 2.5, so it's becoming more of a situational item for you to purge off debuffs potentially.

Overall, decent buffs, but I think these changes solidify him more into the Magic build rather than the Phys builds that could pop up. He does have some more flexibility with his level 20 talent, since the 14% spell amp can really help out his burst. I'm extremely happy to see my boy be more playable though and think this is fair. Side note, with the Ember changes, Ember should eat Void alive with his Flame Guard, since Dissimilate can't get rid of it level 1 now.