I think having something that replaces item rooms with planetariums could be cool, it would have to be at a cost though like having 6 broken hearts or something

have him start with zodiac, give him 3 soul hearts as his health, make a gimmick like he was denied by the stars, which would make the occasional pillar of light strike which would damage you and enemies.

Tainted Mezarim (The Obsessed)

Stats:
- 3-6 soul hearts;
- Pretty same stats as normal version (maybe walk speed little bit higher)
Active item: at sun glance:
- no charges
- gives 6 broken hearts and halves your tear stat (because eye you looked from telescope has been burnt) until next floor
- gives random planetarium item, which will disappear in the next floor
- after use becomes not able to activate until next floor

and that’s not the end!

gimmicks:

- piteously longing: loses half of a heart after clearing room and it can be stopped only by using at sun glance:
- heals 3-6 blended hearts in the next floor
- Also can go into normal treasure rooms ;) (cause damn broken telescope is pretty unbalanced)

trinkets and pickups:

theres 2 options for trinkets:

1) starly second deal - every card will be one of this cards: XIX The Sun, XVIII The Moon, XVII The Stars, XXI THE WORLD (As well their reversed versions if unlocked)

2) witch’s blessing - making a devil deal or paying / satisfying devil (or even key or bomb) beggar gives you a dream catcher effect until the start of the next floor (for planetarium chance)

and as a pickup he would have a one of earlier mentioned cards (XIX The Sun, XVIII The moon, etc.)

Birthright:
You’re done of tears!: you will not lose life by completing rooms
Desperation:
- heals 3-6 blended hearts.
- You’ll gain bloody lust and adrenaline effect (which is boosted by longing gimmick)
- heal 1 blended heart after using at sun glance


e) notes:
- I think that the main theme of this character should be Obsession which is symbolism of isaac’s seeking of something beautiful in his life (because of pathology of his parents of course)
- Remember that's only suggestions, some of them can or should be changed for joyful gameplay, for example adding by more accurate trinket or removing some details
- that's only a proposition, but some unlockables would be pretty addon
- Maybe that opinion will be ignored, but im pleased that I could give something from myself somehow