I've found a bunch of T1 overspawns but no T2+ yet

Mythical copper dagger (tier II)
Damage: 12 to 21

+3 Mana Regen
+3 Critical Strike
+1 to 2 Life per Attack
+1% Critical Flux
+1% Quick Draw

14 ml at level 11

Another...at least we know they're possible

Angelic heal I
Heals: 5 to 15
Mana Cost: 5

+1 Mana Regen
+1 to 7 Mana per Kill
+1% Critical Flux
+4% Wind Mastery

Magical splintered club
Damage: 3 to 13

+1 to 15 Life per Kill

ID: 15470886

My first

Rare fire III
Spell Damage: 13 to 37
Mana Cost: 21

+7% Ice Mastery
+4% Fire Mastery

aka

Rare glyph III
Use Item to Receive Effect
Effect Duration: 15 minutes

+7% Ice Mastery
+4% Fire Mastery

Angelic copper dagger
Damage: 13 to 24

+13 Strength
+1 Vitality
+2% Lightning Mastery
+2% Wind Mastery

ooooooooooof babby!

Just a theory here:

Magic Luck has a % chance to create an overspawn... this happens when an item roll a perfect mod for that tier, it has a % chance to increase the mod up to 1 tier level higher, and a % of the extra is added.

Remember... theory.

my first one ^^

Rare lightning III
Spell Damage: 5 to 55
Mana Cost: 21

+1 to 33 Mana per Kill
+1% Armor Pierce

Rare heal I, Heals: 3 to 8, +2% Life Steal, +1% Earth Mastery

My first, will only post good drops from now on.

Rare copper sword
Damage: 3 to 35

+5% Mana Syphon
+1% Power
Max at tier 2 is 4 syphon right? Testing witg +6 ml lvl 26v