Shield Sphere

Defender
Whenever Shield Sphere blocks, put a -0/-1 counter on it.

Phyrexian Walker

Jhoira's Timebug

{T}: Choose target permanent you control or suspended card you own. If that permanent or card has a time counter on it, you may remove a time counter from it or put another time counter on it.

Gargadon

Trample
Suspend 4—{1}{R} (Rather than cast this card from your hand, you may pay {1}{R} and exile it with four time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Durkwood Baloth

Suspend 5—{G} (Rather than cast this card from your hand, you may pay {G} and exile it with five time counters on it. At the beginning of your upkeep, remove a time counter. When the last is removed, you may cast it without paying its mana cost. It has haste.)

Ornithopter

Rift Elemental

{1}{R}, Remove a time counter from a permanent you control or suspended card you own: Rift Elemental gets +2/+0 until end of turn.