i know this will sound strange , oddly enough , when it comes to any in gaming experience i actually do not overload aerith with any materia or summons . or rather , i tend to give her support materia like sense , enemy skill , or added affect / elemental with a single element or status materia ( ie : poison , lightning , ice / shiva , etc ) . rarely do i ever put a summon on aerith , though if i do , i tend to lean toward shiva and alexander . this mostly is relevant toward roleplay only , though . when it comes to the headcanons of which materia / summons do i like to have on aerith when i write , then that would certainly be shiva & alexander ( and i know its not possible to have alexander on aerith during the og gameplay , as it is acquired after her death by the team ) .
the reason i do not play aerith as a mage ( which it seems implied and canon that she is ) , is for a few reasons : aerith is already overpowered & a healer when we consider her limit breaks . i find no point in putting restore materia on a healer , her limit break will do that . so , i put magic like that on other members . the fact that aerith is also a cetra and can likely wield magic without the use of materia is something else i strongly stand by ( granted we do not experience in this so much in game canon ) . there is also the affect that some materia has against health , by reducing health points . aerith starts with lower health and the last thing i want to do is bog her down with materia that will heavily decrease her hp & by giving her one materia ( ie : ice / shiva ) and pairing it with an elemental materia on her weapon , i can greatly increase her hit points on her weapon . aerith can often times be a good physical attacker if materia is paired right with her / with the right weapon . and this also means i do not have to weigh her down with a bunch of hp+ materia which i do actually avoid for most of my gaming experience . ( at most , i use only one hp plus materia because when they are mastered they are usually enough to have your character at max hp ) .
here are the fun reasons i really like to attach aerith with the shiva & alexander summons when it comes to my roleplay portrayal : i associate ice with aerith because her place of birth & continent in which the cetra migrated is the icicle inn area and though the ice is due to the wound to the planet and jenova , it is a new element that at the time is relevant to aerith and the cetra imo because she is born during the time this is the norm for the continent . i like having this tied to her roots because i also have a lot of headcanons that attach the cetra to lore & mythology of nordic people .
alexander is an easier one to attach to aerith for other obvious reasons , the greek etymology of alexander’s summon name is “ protector of mankind “ which is exactly what aerith is especially in her last act . the fact this is a summon of holy element which is an element aerith knows how to wield , though she may make fun of her holy materia , she understands how it operates ( even if in the beginning of the game we realize it didn’t do anything ) .
thank you so much for this question ! i was really excited to answer this one and it was a great question ! ♥ ♥ ♥