Xander as the brother of Nick Burkhardt that was given up by his aunt Marie after the death of his parents and then fostered by the Harris's for an extra paycheck.

Must Have

= Xander having a close long term protective friendship/mentorship with a good Wesen couple who ensure he turns out to be a good, open minded, down to earth, self confidant man despite the daily negative influences of the Harris's, his classmates, teachers and the Scooby's.

= Xander having won several competitions in Archery, Swimming, Running, Art... thanks to his positive role models and to the displeasure of Willow.

= Xander having his own detailed, disguised, encoded, modern and frank Grimoire {think Charmed Book of Shadows in size/look with a lock} giving the full lowdown/profiles of everything & everyone supernatural {not just the Wesen} without Bias. Includes Homemade Remedies to various conditions, injuries, ailments, poisons & magics.

= Competant, Observant & Artistic Xander with necessary life skills thanks to his mentors > Self Defence & Daily Fitness, Profiling, Languages, Problem Solving, Camp/Hunt/Track/Fish, Handyman, Mechanic, First Aid, Homemaking{Cooking/Housekeeping/Maintenance/Management}, Research...

Xander finds his brother whilst in his teens and they form a close unbreakable bond, particularly when Nick finds out how his brother has been treated and takes him in, moving him to Portland, further ensuring that Xander grows up a good man. 

Xander helps provide Nick with a Solid/Thorough education in the Wesen/Supernatural world pre Grimm so he's not as lost/freaked out when he does become a Grimm  

Challenge – Alex Kent formaly Xander Harris 

• Set during high school for both of them though Alex can be older or younger than Clark

• Both Alex and Clark work through their issues through various mediums = art, music, stories, carpentry, mechanics, cooking...

• Alex is a metahuman with a heightened healing factor, the gifts of Empathy and a more active power such as Force Fields...etc {though nothing that would make everything simple like Telepathy} – Clark also discovers his abilities quite quickly once they meet due to an accident

• Deeply mourning the deaths of best friend Jesse who was like a brother and his secret military brat Boyfriend aka first love = both of whom were the only ones who previously knew of his metahuman abilities

• The Harris's are killed in a fire {doesn't really mourn them, instead mourns for what should/could of been if there was no abuse, neglect, indifference, alcoholism..etc} = does inherit a reasonable amount of money from insurance once the debts...etc are paid

• Alex belongings reduced afterwards to Boyfriend Ninja Motorcycle, Jesse Guitar & a chockablock duffle bag with his clothes, Jesse-Boyfriend Jewelry, Essentials, CD storage books, personal folder{his true Ids-records-paperwork-licences...}, His-Jesse-Boyfriend Journals{packed with art-lyrics-keepsakes-photographs...}, hunter journal, blessed weapons, first aid kit, supplies, odds & ends...etc

• Alex having had experience & previously earning money in the darker aspects of the world – fight clubs, stealing, drag racing, hustling pool-darts-cards, stripping...etc making him much more likely to spot various human threats early as well as call anyone and everyone on their BS or unwarranted hurting/pushing of Clark

• Manages to make his way to Smallville after the Harris's deaths where he's adopted by his aunt and uncle {the Kents} which leads to a new surname, nickname, paperwork, licences, accounts, practical wardrobe, calmer personality{no more joker-slacker facade}, full medical, full education testing, gifting Kents with half of his parents insurance settlement so less money problems for them

• Or alternatively Alex meets Kal whilst living in metropolis, becomes confidants and helps him out - so much so that Clark calls him once he's back to himself and Alex moves to Smallville to be closer to him to help with his issues - afterwards Martha recognises him as her nephew and it then leads to the new Surname, nickname, paperwork...etc

• Alex & Clark bonding very closely as brothers with unconditional and beneficial support, brotherly love, trust, friendship, acceptance, truth, clarity, lack of secrets...{outside of their powers possible secrets could be taking college classes, being stolen at birth or lab created{Alex}, teenage pregnancy...}

• Both of them end up forming a good solid relationship with Lex Luthor despite everyone else's protests which leads to one of them initially dating him and the other dating Bruce Wayne or Oliver Queen as Lex doesn't go crazy or evil though he does still die

• Clark gets over his Lana crush much quicker as he realizes that it all based on fantasy and not reality as well as lets Chloe down gently about her crush

= Xander as the unknown son of Nathan Ford

= Relationship gets found out in one of several possibilities 1) both nate & xander are kidnapped as revenge - force nate to discover & then watch another son die, 2) meet whilst unkowingly doing the same job, 3) xander as the target of the teams con thanks to the manipulations of a mutual enemy

= Xander had a hard childhood thanks to at the very least abuse, neglect, social isolation & loss of a brother, best friend and first love/boyfriend

= Xander slow to trust his dad thanks to his childhood, Nate's own Alcoholism and Sophie hold on Nate{has issues with women thanks to relatives, crap friends & bad ex's}

= Xander as a mix of Nathan, Eliot & Parker in Skill set with his own small business as a hobby{Gay BDSM club-Tattoo Parlour-Carpentry Furniture Store-Motorcycle Garage...}

= Alternatively Xander as a blind hitter who no one knows is blind thanks to his ability to compensate

= Xander slowly forming a strong bond with the team minus Sophie & in particular Eliot as either a Mentor/student, Lovers, Brothers or Best Friends

= Alternative Universe - mpreg, shifters, sentinal, BDSM...etc