User blog comment:R E W S/The Best champion in the League of Legends:Arcturus, The Stellar Morpher (FINISHED)/@comment-1330314-20121203221721

I like the zodiac theme, but honestly you're putting way too many spells on your champion. Thirteen different forms plus three unique abilities each means 39 spells plus 13 passives, which is not only nigh-impossible to remember when playing the champ (the Invoker with 10 spells is hard enough) but also makes it impossible to fight him properly as the enemy, who won't know what they're getting hit with. Additionally, this poses some balance issues, first of all because some of your stats are too high (his base stats, his passives which give him either way too much sustain or too much damage, the scaling on his damaging and healing abilities) but also because he has everything he could possibly want. He has gap-closers, CC, heals, mitigation, burst, debuffs and DoTs, and them some. You need to give your champ a weakness of some sort besides his complexity, either by implementing gaps in his skillset (for example, making him very mobile but also squishy, or very tanky but not very good at DPS) or by making his abilities mediocre all around.

This may not be the best example, but I made a champ on my blog called Rheya, who's also somewhat based on the Invoker and has and element theme. Now, the mechanic with her is that her abilities synergize together to give each other secondary bonuses. This means each spell has a total of three different iterations (not counting their basic form), making a total of 12. Now, first of all I made every iteration similar to lessen the burden of knowledge on her, and even then some people complained that she was complicated. Second, I made it so that she had a wide skillset, but could not benefit from all of it at the same time, i.e. you had to sacrifice some of her advantages to better use others. It's probably not the best example of a model champion out there, but it's just to say that you need to streamline your champ a bit, perhaps giving him only one modifiable zodiac-related ability as his ult rather than making him change entire skillsets in combat.