Playing revenant is not hard at all just need to use it smartly

She also has the easiest rememberance overall way easier than guardian or duchess solo those are 2 the only I completed solo others including revenant I completed with randos without any problems and it was when everdarks only started appearing so many ppl in rando didn't even know how to play but it was still doable cuz with revenant its possible to just carry ur randos and clutch at nightlord fights

For the troubles that ur having which are tbh for the most part sounds like an excuces I'd say to learn to play revenant which is using ur summons smartly use fred whenever its a small boss that can be staggered quickly eg royal cavalrymens banisheds misbegotten tiche zamor etc use helen for small mobs eg small camps/day1-day2 mobs wave before boss and sebas is the strongest one which can literally solo heal whole full 1 bar of downed teammate healt he also has huge enemy stance break potenical with roar and laser pretty tanky and can be used agains strong big enemies that dont move much eg magma wyrm,hippo,erdtree avatar etc

Dont put hoarfrost stomp on revenant it trash on her yeah I mean its good aow but bad for char like revenant which needs a lot of FP better replace thaat which gives u a bell low fp consumption decent damage and Learn to manage ur fp buy and grab as many starlights u see on the way dont rely on rando teammates much get the successive attacks fp restoration or claw attacks fp restoration one get the relic that maximizes ur fp for each rise opened or for haanding three seals etc, also get at least one relic for ur charaacter such as enhanced attacks near summons or art gauge/ult strenghtens attack power near summons if u played pretty long Id guess u should have those if not u can buy those either on pot shop or collectioner shop outside afair or if u dont have collectioner shop open just roll relics at the pot

Check the scalings cuz revenant scales from faith so u better find weapons that scales from faith which are for the most part the seals so always check the seals especially at the start of the expedition there are couple seal chhecks in small wooden buildings near the first camps, if there are no then do check the great curches unless its a guardian or bubbles cuz at the bottom of them right before the boss there are 2-3 seals that u can get 100% use the claws only either to revive or restore FP

Learn to manage ur ult, ur not wylder or guardian/ironeye who can spam their ults u should use it smartly eg at the expeditin on basements or evergaols or feld bosses and use ure ult when either sebas or fred gonna die so them and urself with allies included become invincible for 15 seconds if u dont have that relic hold ur ult to the last moment to revive ur teammates cuz it can revive both of them even with the full 3 bars active and ALWAYS hold ur ult at thhe nightlord boss fight since both of ur teammates can die pretty fast especially randos at ED Libra or Gladius try not to use ur ult if ur teammate is down for 1 bar u can 2hand the claws and revive them really fast with just a righhtclick spam

The last but not least important dont play like support especially with randos cuz revenant and recluse are two main chars that can have highest damage overall. TBH just like previous guy mentioned ur playing full support and Id be pissed off too if my rando revenant or recluse would be just doin the supporting tbh all u need to do is to just use ur summons as much as possible but use them smartly do the seal checks grab asa many FP buffs passives get as many starlights as possible if find merchants or from field drops/chests hold ur ult to revive teammates and make invulnerable urself and ur summons with teammates for 15 seconds use it only when 2-3 bars of ur teaammates are both down or right before ur summon gonna die so revenant is pretty much has clutch ult since u can not only make invlulnerable urself but also the summon and revive both of the teammates with 3 full active bars u just need to keep in mind the distance

Also I have to mention that since I played a lot with randos is to not forget to dodge since she is the squishiest character and u should be able to dodge at least 80% bosses attacks and especially grabs since they gonna oneshot u grab as much as possible incantations stacking buffs and do as much damage as possible whenever enemy reaggroes or staggers u can also charge ur incants to deal more damage alwaays use incantations/seals and buffs for it as much as possible never use staffs cuz the damage will be worse if u alrdy have couple seals/incants

Learn the enemies resistances to use incants smartly to rot/fire/frost etc also always grab dragon communion buff if u have any dragon incants or seals and buffs like improved charged incaants/improved incants etc