I don't know I'm not a game developer and real talk I think it's hard to come up with new mechanics. :(
I mean first you got to think about what kind of character you want like a pirate and than you can work from there.
Oh actually how about something like Dota 2 Visage except less soul assumption and Graves Keepers cloak.
Gets familiars at level one. The champion has low movement speed and is pretty squishy. Casts all abilities from familiars.
Passive| Casting familiar on yourself causes it to dash towards you from a distance, when on you gives extra defenses and boosts your movement speed. You won't be able to cast direct the familiar again for a couple seconds.
When dashing the familiar will avoid all terrain like Aurelion Sol however if damaged the familiar will stop and the passive will go on cooldown for awhile. The farther away the familiar is from you the slower and weaker it and the champion becomes has a global leash.
Q|Stacking ability, skill shot from the familiar that slows attack speed and applies grevious wounds up to 100%, doesn't do damage
W| The familiar begins summoning some sleepy stuff, it slows enemies near the familiar and if they stay near for long enough they fall asleep kinda like Elder Titan. Damaging a sleeping enemy will wake them up. The familiar can move while it is summoning.
E| Familiar becomes untargetable, ghosted, and dashes, if it dashes through enemies you get heal stacks and familiar will heal nearby ally like Rakan
R| Passive: Strengthen familiar stats, attacking the same target as familiar slows the target, causes the detriments the familiar has when being further away from the champion to decrease.
R| The familiar and champion begins channeling from their location, gradually magical energies circle the familiar and there is a large radius. Enemies that touch the magical energies get slowed immensely, take damage, and are grounded. The familiar cannot be stopped from channeling but the champion can. The ability lasts for a long time like I'm thinking Mao'Kai's old ultimate and it drains mana per second.
