@Oscelamo:
1) Sleep is 1 round casting-it takes effect on the following round. Add 1 round of waiting and it is once per 3 rounds. So, essentially, 1 time per encounter.
2) Color spray is very close range every 2 rounds. How many HP they got again? CON of 14 means 4 HP at first level. An arrow is 1d8+str.
3) Scry and die doesn't work; if they teleport, they need to wait 5 whole rounds before they can cast spells.
4) By 12th level, any spellcaster can call creatures with teleport and etherealness at will. If they're cheesy, they can also get astral projection via nightmare. So unless the DM bans teleports for everyone or can get challenges not overcomable by teleport, the game is busted anyway.
5) At 19th level they can have shapechange and 4 more buffs up all day. That's the only problem I see with the class so far-and most casters can do the same.