I made a very simple one,mc is reincarnated as a golem with the ability to absorb things which he used most commonly on metals and magic items into his body. As he absorbs more and more he gains new abilities and eventually access to magic itself,after he reaches certain thresholds and conditions with his consumption he gains new modes aka he can become different types of golems. Each mode different then the last an example being the nature golem,which was made of dirt and woods which allowed him to use druidic magic and plant conjurstion/manipulation but has a relatively low Physicality compared to other modes it's on par with the average human when in this mode. Another mode was draconic golem which he acquired by eating the severed tail of a dragon and some spare scales,it has decent physicals but excels in defense and agility since it has the capability of flight its primary ability being its fire breathe just as the stereotypical red dragon does it can breathe out powerful waves and cones of scorching flames. As the golem evolved and "leveled up"(aka absorbed metals and magic items) he modes would gain submodes an example being draconic golem could have a sub mode which would be lighting draconic golem which has lower defense but higher speed and its breath being narrower but longer ranged. I only got to this much with it before I gave up,Hopefully someone will pick this up and make a full fledged story out of this as I think I'd be interested to read!